Rio Olympics: Swimmer Lochte apologises for 'robbery' saga
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."
Mr Lochte had already left Brazil when the saga blew up but two other swimmers. 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."
How the story evolved
The saga began when Mr Lochte's mother told US media that her son had been robbed.
The swimmer then expanded on the story, describing in an interview how he and three fellow US swimmers were robbed at gunpoint while returning from a club.
He also tweeted that he and his teammates were the victims of a robbery.
Rio police only became involved after seeing reports, and soon said there were inconsistencies in the men's accounts.
On Thursday the head of Rio's civil police, Fernando Veloso, said no robbery was committed against the athletes.
"They were not victims of the crimes they claimed," Mr Veloso said.
He told reporters that one or more of the athletes had instead vandalised a toilet in a petrol station and then offered to pay for the damage.
The Americans paid and left after armed security guards intervened, he said.
One guard had justifiably drawn his gun after one of the swimmers began behaving erratically, Mr Veloso added.
Who are the swimmers?
Lochte is one of the most successful swimmers in history, with 12 Olympic medals, and he once had his own reality television show in the US. In Rio, he swam in two events, winning gold in the 4x200m freestyle relay along with Conger.
Feigen won gold in the 4x100m freestyle relay.
Bentz competed in the 4x200m preliminaries, but not the final. He still received a gold medal after the US team's win.