Sex scandal rocks swimming as Olympic captain stood down in disgrace

Japan swim star Daiya Seto cheated on his wife Yuka Mabuchi. Photo / Instagram

Four-time world champion swimmer Daiya Seto has been dropped as Japan's captain after admitting to having an affair.

Seto, who won the bronze at the Rio Olympics and is the reigning world champ in the men's 200m and 400m individual medley, was found to have gone against the Japan Swimming Federation's 'sportsmanlike conduct standards' and was banned for a year.

However, the good news is the suspension will be backdated, meaning Seto will still be eligible for next year's Tokyo Olympics.

The 26-year-old swimmer, who is married with two kids to fellow swimmer Yuka Mabuchi, resigned as captain after admitting to the extramarital affair.

The Sun quotes Seto as saying: "How can I apologise? I have been asking myself if I can.

"But I think my apology is to continue swimming, restoring the trust of my family, who have been deeply hurt by my irresponsible behaviour.

Japan swim star Daiya Seto cheated on his wife Yuka Mabuchi. Photo / Instagram

"I would like to seriously face swimming with the determination to start over so that my family and everyone will recognise me as a swimmer again."

"I'm really sorry", he added.

News of the affair emerged after a Japanese magazine published a story about him meeting a woman in a hotel.

The scandal has already forced him to cut ties with sponsor Air Nippon Airways.

Seto won gold medals at the 2012, 2014 and 2016 World Short Course Championships and holds short course world records in the 200m butterfly and 400m individual medley.

Seto's ban is another example of Japan's strict policy around athletes dishonouring the country.

World shortcourse breastroke champion Naoya Tomita was suspended for 17 months after he was caught stealing a photographer's camera at the Asian Games.

Four years later at the same event, four members of the Japanese basketball team were sent home and banned for a year after checking into a hotel with prostitutes.

Badminton player was kicked off the 2016 Olympics team when he was found to have lost almost $100,000 at illegal casinos.