SEPANG (AFP) - A Malaysian court dismissed on Thursday (Oct 6) public nuisance charges against nine Australians who stripped down to swimming trunks emblazoned with the Malaysian flag despite guilty pleas from all nine men, Malaysian media reported.

Sessions Court judge Harith Sham Mohamed Yasin said while the men's conduct was "totally inappropriate", they were young and had shown remorse, Malaysiakini reported.

He invoked Section 173A of the Criminal Procedure Code (CPC) to not impose any punishment and instead release all nine with a caution, the report said.

Defence counsel Shafee Abdullah had earlier argued that the court should invoke the provision due to the "trivial" nature of the offence and his clients have shown "remorse" for their actions, the Malay Mail reported.

A spokesman for the nine, aged between 25 and 29, earlier read out an apology in open court, after they had after they pleaded guilty and admitted to an "error in judgment" over their actions during the weekend's Malaysian Formula One Grand Prix in Sepang.

"We apologise sincerely for our actions, which offended the sentiments of people ot this beautiful country.

"We do not have the slightest of intention of undermining this country and its sensitivities," the spokesman said.

The nine, one of whom was Jack Walker, policy adviser to the Australian Defence Minister, said they were unaware of local sensitivities and that stripping down to Malaysian swimming trunks would be construed as offensive.

The other eight men were Timothy Yates, Tom Whitworth, Tom Laslett, Nick Kelly, Edward Leaney, Branden Stobbs, James Paver, and Adam Pasfield.

The racing fans - who were celebrating countryman Daniel Ricciardo's Malaysia Grand Prix win on Sunday - provoked anger in the Muslim-majority country and a debate back home over boorish behaviour abroad by Aussie sports fans.

The defendants arrived at the courthouse in the Malaysian town of Sepang in handcuffs, dressed in suits and looking sombre.

Public-nuisance charges bring a fine while a charge of disrespecting Malaysia's flag can include a jail term of up to six months.

The detainees were dubbed the "Budgie Nine" by Australian media, a reference to Speedo-style swimsuits known colloquially in Australia as "budgie smugglers".

A budgie, short for budgerigar, is an Australian parakeet and the close-fitting swimwear is so named for leaving little to the imagination.

The men, including a staff member of Australian Defence Industry Minister Christopher Pyne, also had quaffed beer from their shoes to emulate Ricciardo, who celebrated his win by chugging champagne from his shoe on the podium.

After pictures and video of the boisterous scenes went viral, the nine men were arrested Sunday at the Sepang racing circuit and ordered held in remand for four days pending possible charges.

The court hearings were yet to begin as of late morning, as prosecutors and defence lawyers appeared to be in closed-door negotiations on how to proceed.

But an AFP journalist saw court staff placing the red, white, blue and yellow swimwear on an evidence table in a courtroom.

While many in Malaysia laughed the episode off, some called for jail terms over the "indecent" display, adding that the swimwear desecrated the country's flag.

Formula One ace Ricciardo Thursday threw his support behind his fellow Australians, calling their celebrations "harmless" and called on the authorities to send them home.

"It sounds like they have learnt their lesson and I don't think they will be doing that again any time soon in Malaysia," the Red Bull driver told Sydney's Daily Telegraph.

"I see it as pretty harmless. I respect the laws in Malaysia but beyond that I don't think they deserve any further punishment.

"In Australia it's a bit different but I'm very sure they didn't intend to offend anyone."

The tabloid Telegraph also got behind the men, writing: "To our recalcitrant, humourless Malaysian friends... Free the Budgie Nine."

Displays of public indecency are not tolerated by authorities in Muslim-majority Malaysia, with foreign offenders typically slapped with a fine before being deported.

Australian Foreign Minister Julie Bishop said the men were being offered consular support but warned there were limits to what Canberra could do.

"They are facing certain charges and what might be seen as a foolish prank or Aussie blokey behaviour in Australia can be seen very differently in another country," she told Channel Nine.

"You have to respect the laws of the country you are visiting."