£9 billion Olympics 'good value', says spending watchdog Crucially, the Games passed off without major transport disruption or security incident. The scale of the construction programme and the fact that it was completed on time and within budget is impressive. Fireworks explode over the Olympic Stadium during a rehearsal for the opening ceremony (AP) Boris Johnson hailed the report, saying: "The doomsters and Olymposceptics have been confounded yet again." The National Lottery stands to be reimbursed for much of its contribution, which will be available to distribute to good causes. This includes a share in the proceeds of the future sale of the Olympic Park. Also in the report, the NAO warned that the Cabinet Office would have to show strong leadership in bringing together the various organisations responsible for coordinating the legacy of the Games. Bradley Wiggins on his way to winning the gold medal in the men's individual time trial (AP) The cost of the Olympic Delivery Authority's programme to build venues and infrastructure is expected to be £6.7 billion, compared to the £8.1 billion that had been made available in the 2007 budget. The NAO said success of the Games spanned from the opening and closing ceremonies through to the 11 million tickets sold for the Olympics and Paralympics, while meeting the huge challenge of recruiting and deploying 70,000 volunteers. British athletes won 65 medals, including 29 gold, at the Olympics, and 120, including 34 gold, at the Paralympics. Hannah Cockroft stormed away from the field to win GB's first athletics medal at the Paralympic Games (Getty Images) Amyas Morse, head of the NAO, said: "Few could have envisaged how successful the London 2012 Games would turn out to be." But the Games had faced an added £514 million bill to cover venue security costs, after contractor G4S fell short in supplying the agreed number of security guards, and extra troops and police were deployed to plug the gap. The NAO's post-games review said that 135,000 additional days of military personnel time had been provided, at a cost of £36 million, according to figures supplied by the Ministry of Defence. It said the Home Office had calculated that the police service provided 12,000 shifts at an estimated cost of £6 million. Margaret Hodge, chairman of Parliament's Public Accounts Committee, said the exception to the smooth build-up and delivery of the Games was G4S's "unacceptable failure" to fulfil its contract. Boris Johnson said: "This report puts into black and white the scale of the achievement in organising such a successful festival of sport, and pays tribute to the many different players who helped make the Games the greatest show on earth." Sports minister Hugh Robertson said the UK can look back with pride "on an outstanding Olympics and a groundbreaking Paralympics, which showed Britain at its best."