One of the nine Australian men detained in Malaysia for publicly stripping down to their underwear at a Formula One race has quit his job in cabinet minister Christopher Pyne's office.

Jack Walker tendered his resignation to the Defence Industry Minister on Saturday, shortly after returning to Australia.

"Jack Walker has today offered me his resignation and I have accepted it," Mr Pyne said in a statement.



"Jack indicated to me his deep regret for causing any embarrassment to the government and apologised.



"One lapse of judgement does not detract from the fact that Jack has been an outstanding staff member, a significant contributor to my office since late 2013 and I believe he will have a bright future."

Mr Walker, a 26-year-old policy adviser, dropped his daks alongside eight friends at the Grand Prix in Sepang last Sunday, revealing budgie smugglers emblazoned with the Malaysian flag.