Two lighting contractors who defrauded the Millennium Dome company out of £4m have been jailed by a London court.
The Dome is currently being redeveloped
The judge said Simon Brophy took advantage of "chaos" in the building of the Dome and jailed him for 56 months.
Brophy, 39, of Wakefield, West Yorks, admitted conspiracy to defraud, corruption, providing false information and moving crime proceeds from the UK.
David Gordon, 44, from the Isle of Wight, admitted conspiracy to defraud and received a sentence of nine months.
London's Southwark Crown Court heard Brophy used his position in charge of lighting at the Dome to ensure a lucrative contract from the New Millennium Experience Company (NMEC) went to Pro Design - a firm he owned.
The contract was initially worth £1.9m, but in the end costs were inflated to £3.9m.
Police found Brophy had set up the firm, of which Gordon - from Seaview, Isle of Wight - was listed as a director, for his own benefit.
Brophy had channelled money abroad to accounts in Latvia, Switzerland and the US and funded a luxurious lifestyle.
As well as an expensive flat in London's Docklands, Brophy also bought property in Florida, a helicopter and jewellery for his wife.
The NMEC became suspicious in September 2000 and called in the Metropolitan Police.
Much of the money in Brophy's accounts was withdrawn after suspicions started to be raised. On one occasion he left a Swiss bank with £236,000 in a briefcase.
Five other people were charged in connection with the case but were found not guilty or had the charges discontinued.
Passing sentence, Judge Christopher Hardy said Brophy became an opportunist after being appointed the Dome's head of lighting in 1998.
The judge said: "I accept you had no intention before that appointment to defraud but I am quite satisfied that very soon thereafter you dishonestly and corruptly took full advantage of the considerable degree of chaos you found NMEC was involved in in having to commit to an unmissable deadline."
"Plainly you milked NMEC for all you could and you set up a chain of bank accounts in the UK and across the world to launder your ill-gotten gains estimated in excess of £1m."
The court heard Brophy had appointed his wife as his effective deputy. She was cleared of any wrongdoing in a previous trial.
The front company itself operated out of a one-room office in Greenwich, with Ruth Barclay, Brophy's mother, as one of the directors. She was unable to stand trial because of ill health.
The Millennium Dome was recently renamed The O2 and is currently being redeveloped.
It will feature a British music hall of fame, a jazz and blues street, a 1,800-seat theatre, and a 2,200-person capacity music club alongside restaurants, bars and an outdoor arena and piazza.