Amaechi was the first Briton to make a big impact in the NBA
Former GB basketball star John Amaechi has raised concerns that the legacy promises made by the London Olympic team are not being followed through.
Amaechi, an ambassador for the 2012 bid, holds a place on the London Organising Committee for the Olympic Games (Locog) Diversity Board.
He told BBC Sport: "I'm not convinced the language used around legacy when bidding is the same we are using now.
"It was a promise and I feel implicated because I was part of the bid."
He added: "I agreed to show the IOC around the Dome, as it was then, [now the 02 Arena] because I believed it was a valuable legacy that could be offered."
London's bid to win the Games in 2012 was heavily based around increasing participation in sport.
The then Prime Minister Tony Blair said: "Our vision is to see millions more young people participating in sport."
Lord Seb Coe, who fronted the bid, added: "London's vision to is reach people, young people, all around the world."
But Amaechi said: "Prior to winning the bid it was all about pretty children and the five host boroughs and a long-lasting human legacy that wasn't just about buildings.
"Now I'm not hearing so much from Locog about legacy outside of physical regeneration - outside of buildings or parks - and I think it's really important they keep their eye on the ball, making sure there is a tangible legacy for people.
"Whether it be in terms of inclusive programming in the areas or increased opportunities for local people to be involved as volunteers or suppliers engaging small business in local area or some sort of more permanent partnerships between sponsors of Games and people who are most affected inside those boroughs."
Everyone is committed to delivering legacy
But a spokesperson for Locog answered: "We are very happy to update John on the huge amount of work being done to deliver a sporting and economic legacy.
"From the Adizones [outdoor gyms] in London boroughs, to the business contracts won by SMEs [small to medium enterprises] inside and outside London, to the hundreds of local people working on the Olympic Park, to the role our education programme programme is playing in schools, to the jobs and skills we are creating throughout the whole of this project.
"The language has not changed. Everyone is committed to delivering legacy."
The spokesperson added that Locog's role was to stage and host the Games and that it was the responsibility of their stakeholders to deliver its legacy.
She added that one in 10 of the people working in the Olympic Park was previously unemployed.
Amaechi is Britain's most successful basketball player after spending several years in the NBA with the Cleveland Cavaliers, the Orlando Magic and the Utah Jazz.
Now retired he has his own legacy in the form of a basketball centre in Manchester that he built and put his name to.
"We are a centre of excellence, having the best basketball facility and best basketball players in the country," he added.
"We have been for some time, over last nine years we have just under 50 young people who have gone to scholarships in the USA or professional in Europe - which is a pretty good turnaround for a facility.
"More importantly we have 2,000 kids going through our doors. We have found a way to combine an excellence model that doesn't exclude everyone else. That truly is legacy working.
"We are not just a community centre for the ugly children of society, the ones we think of as feruled youth to run around in.
"Manchester is a good example of how facilities can have ongoing legacy use but for the most part lets not pretend that the Olympic Stadium is going to be some hub for community sport.
"I don't see how that's possible, if it is also going to be a home for professional sport how it is even affordable on a practical basis?
"So it is really important that, given some of these legacy buildings are not actually going to be that much use for the communities - you won't be able to pop down the Olympic arena to play badminton or the 02 to play five-a-side - that's why we have to manifest other ways for legacy to present itself to local people."
John Amaechi will be commentating on the NBA game between Chicago Bulls and Utah Jazz at the O2 Arena on the BBC 5 live, the BBC Sport website (UK only) and the Red Button on Tuesday, 6 October.