Former Glasgow gangster Paul Ferris has said seeing a film about his life on the big screen was "an emotional rollercoaster".

The Wee Man, which stars Martin Compston as a younger Ferris, tells the story of how he entered the city's crime underworld, working his way up the ranks as an associate of Arthur "The Godfather" Thompson Sr.

Bullied as a child, Ferris claims he was born into a life of crime and the film makes allegations of police corruption and a feeling that there was no way out.

Watch the video of Paul Ferris at The Wee Man press conference above.

Watch our video interview with stars Martin Compston and Laura McMonagle

His close working relationship with Thompson Snr is said to have irritated the gangland boss's son, Arthur "Fat Boy" Thompson Jnr (played by Stephen McCole), causing rival boss Tam McGraw (John Hannah) to identify "a weak link".

Ferris, now 49, was cleared of the 1991 murder of Thompson Jr when a jury returned a not guilty verdict at the High Court in Glasgow, following one of Scotland's longest-running criminal trials at the time.

Thompson Snr "declared war" on Ferris after his son's death and, in an apparent "revenge attack", two of Ferris's friends, Joe Hanlon and Bobby Glover, were found dead on the day of Thompson Jr's funeral.

Ferris said: "It was very humbling (to see the film), I thought it was an emotional rollercoaster.

"The best way was to be up front and honest about it.

"During the first 15-20 minutes of it when I first saw it in London I felt as though I needed fresh air but I didn't want to give the wrong impression by standing up, because I was sitting at the front. To walk out might have made other people think 'where's he going', or 'what does he not like about the movie?'.

"I look back on it and it was trigger mechanisms from my childhood that I'd put to the back of my mind. Watching them unfold on the screen was a bit queasy. I felt like I needed to go for fresh air. I felt claustrophobic. I had that many emotions running through my mind.

"I don't think I was adequately prepared for it. I was the first guy out the door when it finished."

Compston, 28, who is from Greenock, Inverclyde, said he was "absolutely delighted" to be cast as Ferris.

"I grew up with the story of Ferris throughout my life. I read it all in the papers, I saw it all in the news and I read his book (The Ferris Conspiracy)," he said.

"I remember years ago there was a picture of Paul and Robert Carlyle coming out a hotel with the caption 'Robert Carlyle to play Paul Ferris' and I was absolutely gutted.

"I remember thinking I was far too young for it and I felt like it was a bit of a missed opportunity.

"Then that didn't happen - the film was in and out of production for years - and out of the blue I got a call one day saying 'do you fancy playing Paul Ferris?' So I was really chuffed."

The Sweet Sixteen star said Ferris offered him some advice but, on the whole, gave him space to get on with the role.

"Paul was great in that he totally backed off and just let me do it," he said.

"We had a lovely chat before the film and then he just left me to it.

"I think he probably gave more of his advice to the director Ray (Burdis) on the script and stuff. And that's who I've got to trust because it is Ray Burdis's impression of Paul I'm playing; it's not a documentary."

One part of the film he wanted to make sure is historically correct is the moment Ferris walked free from court, cleared of Thompson Jnr's death, when he was apparently wearing an "ugly tie", Compston said.

"The era we mainly focus on in the film is the early 90s and the fashion at that time wasn't the best, as Paul's ties illustrate," said Compston.

"Obviously we had artistic licence for everything but there was one thing I wanted to be absolutely perfect.

"It was this scene where Paul came out of the High Court after being found not guilty of Arthur Thompson Jnr's murder and he did this weird pose to the crowd.

"But he had this horrible, horrible tie, it was like a green and blue mash-up thing, and a weird suit.

"It was probably quite typical of the fashion at the time but it was just something that stuck in my head and I thought 'if I'm going to do that, I want it done right'."

The film, in cinemas on Friday, has come under fire from critics who claim it glamorises crime.

Scottish Labour justice spokesman Lewis Macdonald MSP said: "Glorifying crime or criminals simply adds insult to injury for the victims, and any film which sets out to glamorise the criminal and ignores his victims is starting from the wrong place.

"Those who have suffered as a result of this man's criminal activity will be made to go through it all again because of this film. Perhaps he will recognise that and actually hand over any income or benefits in kind to his victims and their families. It would not compensate them for their suffering, but it would at least show good intent."

Director Ray Burdis, who also produced The Krays, claims Strathclyde Police and Glasgow City Council did not allow the film to be shot in Glasgow "because of the subject matter".

A police spokeswoman said that this is "wholly incorrect" because any permission would be given through the local authority.

"We did not try to ban this and any suggestion that we did would be wholly incorrect," she said.

Burdis said: "Things have been taken a bit out of proportion, but Strathclyde Police and Glasgow City Council certainly didn't make us feel welcome.

"When you're making a film you have to shut down roads and other logistical things. They issued a statement saying they were not going to offer any help.

"I understand they've got issues - you know, Glasgow Smiles Better. So they don't want to dig up the sordid past of the city.

"It's just a shame that we weren't allowed to film it here. We could have brought a few million quid into Glasgow and given people employment. That's my only beef."

A council spokesman said: "We didn't try to ban the film and any suggestion that we did would be inaccurate. Glasgow Film Office, which is run by the council, was approached by the producer to establish which bodies should be contacted to enable filming to take place in locations across the city and asking for contact details for the police.

"We told the producer that the GFO (Glasgow Film Office) did not have the authority to approve locations. We gave him contact details for the police but provided no further assistance."

Instead, The Wee Man was mainly filmed in a London studio.

Ferris, who lives in Ayrshire with his wife Carolyn, said he has changed his ways and hopes the film will show younger audiences that there is no glamour in crime.

"It's just unfortunate it is an 18 but I know kids will eventually watch it, in the same way that Grand Theft Auto shouldn't be played by kids but they do anyway," he said.

"We had a lot of good feedback on The Ferris Conspiracy from parents who actually gave their teenagers, who were going to go on a particular path of gang culture and different things, the book to read on the basis of saying 'is this the life you want to lead?'

"I've spent 13 years of my life in prison and there's no glamour attached to that, especially when your family goes away from the visiting room and you're left alone.

"So, I hope the message the people take out of this, especially younger audiences in conjunction with their parents or guardians, is for them to take a look at this movie and think 'is this the life they want to lead'?"

On the film as a whole, Ferris said: "Ray (Burdis) has obviously used some artistic license within the movie.

"It's not for me to say how good or bad his artistic license is. It's Ray's interpretation on how he felt from gathering other sources, about what could have happened, what might have happened and what did happen.

"I think you ought to leave that to an audience to decide, either the fact or the fiction, and in some aspects the truth is far harder to believe sometimes than fiction.

"I think Ray nailed it 90%, and the 10% is his artistic license."

The Wee Man also stars Lauren McMonagle and Patrick Bergin.