AS we sit in the BBC Scotland canteen high above the River Clyde, Joe Hullait is reflecting on his adventures with Scot Squad, the comedy mockumentary series that charts life in the line of duty for a fictional Scottish police force.

It is a hilarious spoof, yet every so often some unsuspecting viewer is taken in by the show's fly-on-the-wall filming style. "There seems to be more of that this series for some reason," muses Hullait. "It is great for us and we get a real kick out of people thinking it is real.

"A lot of mockumentaries don't have the same attention to detail. We are always trying to follow the rules of documentaries. So, it is flattering if someone does think that."

Hullait, 30, was part of a Channel 4 production trainee scheme and arrived in Glasgow in 2010 for a placement with The Comedy Unit, the TV production company that has brought us Rab C Nesbitt, Still Game and Chewin' The Fat among others.

"It was within a month of starting there that I came up with the idea for Scot Squad," he says. An avid viewer of real-life documentaries such as Road Wars and Police Interceptors as well as a fan of the improv style of US comedian Larry David on Curb Your Enthusiasm, Hullait drew from both.

The pilot aired in 2012 with the first series following two years later. Scot Squad quickly became cult viewing thanks to fan favourites such as man child Bobby and long-suffering Officer Karen, played by Darren Connell and Karen Bartke, and Jack Docherty as Chief Commissioner Cameron Miekelson.

Testament to its success, Scot Squad won the television scripted category at the Bafta Scotland awards last November. Series five is currently gracing our screens featuring guest star appearances from John Gordon Sinclair, Lorraine Kelly and Sir Tom Hunter among others.

"Bringing in new characters does help massively in keeping things fresh," says Hullait. "As the show goes on and more people have seen it, it is easier to attract certain people. This year I think everyone we asked said yes which was brilliant."

Who has been his favourite guest star this year? "Lorraine Kelly. She was fantastic. It was her idea. She tweeted: 'My dream is to be in it.' I thought: 'That's easy.' She was great fun and happy to take the p*** out of herself.

"We said: 'Would you mind saying bad things about Piers Morgan?' and she took that on with delight. A lot of people would not be willing to do that."

As well as being the show's creator and writer, Hullait provides the breathless and dramatic, scene-setting narration. He is particularly proud of the line: "Lewis Hamilton may not be from Scotland, but all over Scotland from Lewis to Hamilton, drivers love speed …"

Any other narration gems from the vaults? "There was one where a guy has gone to play bowls. He has been drinking and gets arrested," recalls Hullait. "I say: 'He may have a strong arm on the lawn, but now he's under the long arm of the law.'"

READ MORE: The world according to Scot Squad star Jack Docherty

Starting out, Hullait never imagined Scot Squad would achieve such longevity. "Originally it was just great to get one series. But then, once you get three, you think: 'Well, why not do 10?'"

He is rarely short on ideas. The morning we meet a video is doing the rounds showing an emu running along the A82 between Fort William and Inverness. Hullait was quick to post on Twitter as the fictional Miekelson about plans for a "mounted bird division".

Any time there's a funny police-related story in the news, he jots it down. "If we do a series six – there are no plans for it at the moment but if we do – I have a hundred ideas already."

The eldest of three children, Hullait was born and brought up in Slough. His mother, a nursery admin assistant, hails from Greenock and Hullait lived there briefly as a young child. His father, a scaffolder, was born in Punjab in northern India and moved to the UK aged five.

"He sounds like a cockney," says Hullait. "That was great fun for my Scottish grandparents when they told my mum there was a 'nice English man on the phone' – this was the 1980s – and then they opened the door and were really confused."

There were signs of Hullait's future career path from an early age when he saved up money from a paper round to buy his first video camera. "At school, I was always writing scripts and performing. I went to a grammar school which was academically selective, but I was hopeless at things like science.

"In an art lesson when I was 11, you had to draw how you imagined yourself in 20 years. It was a bit over-ambitious, but I drew the Hollywood sign with me standing in front of it wearing a suit, next to a limo, on a mobile phone and holding an award."

That wasn't the only aspiration he toyed with. "Weirdly when I was a kid, really young, I wanted to be a policeman," says Hullait. An amateur psychologist would have fun with that one. He smiles. "Even a few years ago, well, when I say I considered it, I mean for about 10 minutes …"

Hullait studied English literature at Queen Mary University of London and did a year at the University of Richmond in Virginia where he "watched a lot of American comedy on TV". Back home and skint, he took a campus maintenance job to pay the bills.

"On my 21st birthday, I had to work a nine-hour shift because no one would take it," he recalls. "I was so fed up." It proved a catalyst to pursue his dreams of working in television. A switch flicked in his mind. "I thought: 'Why not try and do the really cool thing?'" says Hullait.

"I was extremely lucky to have ended up with The Comedy Unit and for all of that to have happened so quickly. I still have a lot of ambition and hard work to do, but I think in the last year or so I have settled into a rhythm and I'm doing a good job."

READ MORE: The world according to Scot Squad star Jack Docherty

Hullait swapped London for Glasgow as a full-time base last year ("I moved up to the West End a week after winning a Bafta," he jokes) where he lives with his girlfriend, who is a primary school teacher, and a cat called Precious.

He has a raft of projects in the pipeline including penning a novel and working on the debut series of topical satire show, The State of It, alongside writer and comedian Robert Florence, known for Burnistoun and Legit.

"The pilot went out last year and we're now doing a six-part series," says Hullait. "I'm a series producer and co-writing it. We are at the planning stage with that."

Before then Hullait is set to launch a series of 10-minute shorts for BBC iPlayer Exclusives – mini Scot Squad spin-offs – called The Chief Does Edinburgh and Scotland Unsolved.

The Chief Does Edinburgh stars Jack Docherty and Hullait describes it as "like Michael Portillo's great railway journeys" but exploring Edinburgh, a city that Miekelson proclaims to have known "as bairn, bobby and now broadcaster".

Crime author Ian Rankin, who previously had a one-off guest star role in Scot Squad, makes a cameo. "The Chief looks at Edinburgh literature, geography and history – Ian Rankin helps him with the literature episode," says Hullait.

Scotland Unsolved sees the detectives from Scot Squad, played by Julie Wilson Nimmo and Louise McCarthy, examining paranormal cases – ghost and UFO sightings, mysterious disappearances and the Loch Ness Monster – in what is dubbed the "Unexplained Happenings Unit".

"It is real mythology that people will recognise," says Hullait. "We see them talk about the crime and then investigate it mockumentary-style, chatting it through and coming up with theories. I would love to do spin-off ideas with the other Scot Squad characters. There is scope in all of them."

Scot Squad is on BBC One Scotland, tonight, 10.35pm with new episodes on BBC Scotland, Thursdays, 10pm. The Chief Does Edinburgh is available on the BBC iPlayer from May 9 at 10.30pm. Scotland Unsolved will air on BBC Scotland on 18 May at 10.50pm

JOE HULLAIT: LIFE AND LOVES

Career high: Starting the production company Belter Studios with Ewan Denny last year. We had our first commission together for the BBC, a series of comedy shorts with Hings author Chris McQueer for iPlayer.

Career low: Cleaning tables at Royal Ascot outside the Royal Enclosure. We weren't allowed to buy food from the premises and had to eat stale peanut butter sandwiches.

Favourite film: Four Lions.

Last book read: Down and Out in Paris and London by George Orwell. I'm currently reading a book of poetry by Lemn Sissay called Rebel Without Applause.

Best trait: A lack of concentration. Working in comedy it is good to have lots of different thoughts bubbling away at once.

Worst trait: A lack of concentration. There are times when I need to focus one thing and find it incredibly difficult. I can do it – I don't want it to sound like I'm not a functioning adult.

Best advice received: My dad told me to "always wear a belt in case you have to hit someone with it". Which I have never done. But it sounds helpful.

Biggest influence: I am a big fan of Curb Your Enthusiasm. The scripting method for that is the same as Scot Squad. My brother gave me a book of story scripts from Curb Your Enthusiasm about a year before I came up with Scot Squad and it had a massive influence on the process.

Favourite meal: Lentil curry and garlic naan. I recently became vegetarian.

Favourite holiday destination: New York.

Favourite music: Stevie Wonder, particularly the album Innervisions.

Ideal dinner guests: Peter Tatchell, Ian McEwan, the fictional character Selina Meyer from Veep, Larry David and Leon from Curb Your Enthusiasm, Tina Fey, Nicola Sturgeon, Julie Wilson Nimmo, Louise McCarthy and Chris McQueer.