BRITISH athletes are unlikely to win as many medals at the Rio Olympics as they did at London 2012, the head of funding body UK Sport has said.

UK Sport has invested £347m of public money in Olympic and Paralympic athletes in the build-up to Rio 2016, and from the outset has targeted the medal haul at Rio 2016 being higher than the 65 Olympic and 120 Paralympic medals won by Britain in London.

But with a year to go to the start of the Rio Games, UK Sport chief executive Liz Nicholl said it was "not probable but possible" that the goal would be reached. A final medal target will be announced a month before the start of Rio.

Other recent host nations Australia, Greece and China experienced a 14 per cent, 75 per cent and 12 per cent drop respectively in their medal tally at the following Olympics.

Nicholl said: "It's an aspirational goal and other host countries have all seen drop-offs. It's not probable but it is possible.

"As every year goes by we have a clearer picture of what is possible. The results of this summer will be a really good indicator of where we are in terms of achieving that aspirational goal.

"With each sport, after this summer's results we will review the realistic medal targets and announce the actual target in the month leading into the Games.

"If it was easy then other host nations would have done it in the past. The percentage drop-off has been quite significant."

Nicholl insisted UK Sport was not moving the goalposts from its original target.

She added: "We are not downplaying expectations. It's always been the case coming through London that it was very clear that there was an appetite for aiming to do what no host nation has done before.

"It has shaped the direction the sports have taken in terms of what we have focused on, so there is no letting up in terms of aspiration.

"I would be very disappointed if 66 [Olympic] and 121 [Paralympic] did not fall within the range of possibility but we will not shy away from telling it as it is."

Nicholl added that the future funding of elite sport would in part be determined by success at Rio, though Government policy may change before that as part of its public consultation on sports strategy launched on Tuesday.

The British Olympic Association [BOA], meanwhile, has launched a campaign of 'Olympic Greats' – eight Olympians who will act as mentors for the athletes competing at Rio, offering advice to the athletes and their families.

They are: Ben Ainslie (sailing), Becky Adlington (swimming), Chris Hoy (cycling), Anthony Joshua (boxing), Denise Lewis (athletics), Steve Redgrave (rowing), Sarah Stevenson (taekwondo) and Beth Tweddle (gymnastics).

The BOA is also launching a new online fan club with free membership to try to boost support.

Bill Sweeney, the BOA chief executive, said: "Our nation's support, pride and optimism spurred Team GB on to greatness during the London 2012 Olympics. It is vital that when they compete in Rio our athletes feel that wave of great support once more and know that the nation is with them, inspiring them to achieve great performances."

Ainslie said: "I'm very proud of our Olympic heritage and being a part of that, and I am delighted that I can help support the next generation of Olympians through my role as a Team GB Great.

"When you're out there competing, especially when competing overseas, it is really important to have the support of the nation behind you."

There will be around 350 British athletes in Rio compared to 541 in London and Team GB is likely to compete in 25 of the 28 sports including two new sports - rugby sevens and golf. The three sports with no British involvement are set to be football, handball and basketball.