US swimmer Ryan Lochte has apologised for his behaviour in Rio and "for not being more careful and candid".

The gold medallist had claimed that he and a group of fellow US swimmers had been robbed at a petrol station.

But CCTV footage contradicted that story, showing the men had vandalised the petrol station after partying.

The International Olympic Committee (IOC) has set up a disciplinary commission to investigate the incident and the four athletes' behaviour.

On Friday Mr Lochte tweeted: "I should have been much more responsible in how I handled myself and for that I am sorry."

He said he had waited to issue the statement until it was clear that his teammates would be returning to the US.

Rio's Mayor, Eduardo Paes, accepted the Americans' apologies:

"I confess that my only emotion towards them is pity and contempt," he said.

"It's a shame that they're such weak characters, that they have such personality flaws and it's up to the American Olympic Committee to sort it out."

Gunnar Bentz and Jack Conger, were pulled off a flight in Rio and questioned by police over their version of events before being allowed to leave.

Their teammate Jimmy Feigen was briefly detained and has now agreed to pay nearly $11,000 (£8,416) to a Brazilian charity over his involvement in the dispute.

Mr Lochte, 32, wrote:

"It's traumatic to be out late with your friends in a foreign country - with a language barrier - and have a stranger point a gun at you and demand money to let you leave....

"I am very proud to represent my country in Olympic competition and this was a situation that could and should have been avoided.

"I accept responsibility for my role in this happening and have learned some valuable lessons."

The United States Olympic Committee (USOC) has since apologised to Brazil.

"The behaviour of these athletes is not acceptable, nor does it represent the values of Team USA or the conduct of the vast majority of its members," a USOC statement said.

"We apologise to our hosts in Rio and the people of Brazil for this distracting ordeal in the midst of what should rightly be a celebration of excellence."

(BBC)