The AOC has reversed its decision to ban Australian swimmer Emma McKeon from attending the Rio Olympics closing ceremony, after she wrote a letter of appeal, Australian chef de mission Kitty Chiller said.

McKeon and Josh Palmer, also a swimmer, had been disciplined by the AOC for breaches of team protocol after Palmer said he was robbed on a night out, and both failed to return to the Olympic Village.

But Chiller said she was persuaded to change her mind, allowing McKeon to attend tonight's official team dinner and participate in Monday's (AEST) closing ceremony, after the swimmer wrote a letter with a tone indicating she understood AOC protocols.

Chiller said McKeon now understood the impact and potential consequences her actions had on team security.

Chiller rejected any notion her decision was pressured by public opinion, saying those who objected to the decision did not know what it was like in Rio.

"Rio is a very different city to Melbourne, Sydney or Brisbane," she said.

"It is a dangerous city and that night could've ended in tragedy for Emma."

McKeon has won four medals in the pool in Rio — gold in the 4x100m freestyle relay, bronze in the 200m freestyle, silver in the 4x200m freestyle relay, and another silver in the 4x100m medley relay.

Palmer finished fifth in his heat of the 100 metre breaststroke on day one of the Games.

Curfew imposed on team members after incident

Earlier, Chiller said the pair left a nightclub in Copacabana in the early hours of Wednesday morning (Rio time).

"McKeon chose to stay the night with swimming friends in the Copa district without informing team management," her statement said.

"Palmer headed to a beach kiosk with a friend and continued drinking. The others headed back to the village and did not breach any rule.

"Palmer has told officials that after his friend left he was approached by a man who forced him to withdraw $1,000 in cash from a nearby automatic teller machine.

"Palmer was found later by two businessmen in the Copa district who reported that the swimmer was disoriented and had lost his wallet and phone."

The businessmen phoned the Australian Consulate who contacted the head of security for the Australian Olympic Team, Greg Nance.

Palmer has chosen not to report the incident to police, Chiller said, despite being advised to do so.

"We're not able to investigate any further and obviously we can't force him to go to the police," she said.

Chiller said the pair must remain in the Village between 8:00pm and 8:00am local time and only travel to sporting events in official Rio 2016 transport during the day.

The swimming team management also imposed a 2:00am curfew on all team members for the rest of the Games.