Sydney - Australian Olympic swimmer Jarrod Poort has been banned for 12 months for failing to make himself available for doping tests, officials said on Thursday.
Poort, who swam in the 1500m at the 2012 London Olympics but switched to the open water events at Rio last year, waived his right to appeal.
"At the end of the day people make mistakes and that's what I did," said Poort, who won hearts with a gutsy effort in the 10km open water race in Rio, leading the first 9km before being caught on the final lap to finish 20th.
"It was remiss of me to neglect a management system that must be shown the full respect it deserves and it is a very embarrassing situation to now be in."
Under anti-doping rules, athletes are required to keep authorities informed about their location for one hour every day so they can be quickly found for out-of-competition testing.
Poort neglected to do so three times.
Swimming Australia chief executive Mark Anderson said his organisation had long been a strong and vocal advocate for clean sport and swimmers must follow the rules.
"Both Swimming Australia and our athletes have been very clear on our position both here in Australia and internationally," he said.
"Jarrod has taken responsibility for his filing errors and we continue to work with and support Jarrod as best we can to support him through this process."
Fellow Olympic swimmer Thomas Fraser-Homes suffered a similar fate in June, while Australia's Rio Olympic silver medallist Madeleine Groves could also face a ban for the same offence.