CANBERRA, Australia (AP) — Nine Australians, including a government adviser, have been arrested in Malaysia for stripping down to their briefs and drinking beer from shoes after Australian driver Daniel Ricciardo won the Malaysian Formula One Grand Prix, officials said Tuesday.

Government officials confirmed that Jack Walker, adviser to Defense Industry Minister Chris Pyne, was among the men aged 25 to 29 who were arrested after they stripped down to Budgy Smuggler-brand swimsuits decorated with the Malaysian flag in full view of thousands of spectators at the Sepang race track Sunday.

Pyne's office said the matter was being "handled appropriately" by the Australian High Commissioner in Malaysia.

"Until we have a clearer picture of the process at hand, it would be unwise to comment further," a government statement said.

District police chief Abdul Aziz Ali said Tuesday that the men were being investigated for "intentional insult with intent to provoke a breach of peace" and public indecency.

He said police would submit a report to prosecutors, who will decide Thursday if the men will be charged. Abdul Aziz told the AP that the men face up to six months in jail, a fine or both if they are found guilty.

Sepang International Circuit chief executive Datuk Razlan Razali told the New Straits Times website the men deserved to be locked up and have action taken against them.

"This shows a huge lack of respect to us as Malaysians; this is stupid behavior from foreigners who have no sense of cultural sensitivity and respect," he said.

"It embarrasses their own country as well — it gives Australians a bad name," he said.

Australian Deputy Prime Minister Barnaby Joyce said the men's decision to strip down was inappropriate and ill-advised.

"You're in another nation, you've got to be careful in what you do," Joyce told reporters in Canberra. "But I'm sure — well, I'm hoping — the Malaysians will understand that I don't think there's any real malice in it. Stupidity? Obviously. Malice? No."

Treasurer Scott Morrison told Sydney Radio 2GB the arrests were a reminder for travelers to know local laws and respect them. The government already warns travelers that there are conservative standards of dress and behavior in many parts of Malaysia.

Opposition leader Bill Shorten declined to discuss Walker's behavior, saying he did not want to jeopardize a complex situation.

"It's incredibly serious when an Australian gets arrested overseas," he told reporters.

Don Rothwell, an Australian National University expert on international law, doubted Malaysian authorities would treat the Australians harshly.

"The Malaysian government will be sure to make sure that its international reputation as a tourist destination for the Grand Prix is not too damaged," Rothwell told Australian Broadcasting Corp.

Associated Press writer Eileen Ng in Kuala Lumpur, Malaysia, contributed to this report.