But just three weeks after a successful finish of the great yacht race, Rohan Arnold has found himself in a Serbian jail cell suspected of having ties to an international drug syndicate that tried to smuggle more than a tonne of cocaine into Sydney.

The 44-year-old, together with Australians Tristan Waters, 34, and David Campbell, 48, and a Lebanese man, were dramatically arrested at gunpoint in a five-star Belgrade hotel on Tuesday.

They stand accused of being connected to the discovery of 1280 kilograms of cocaine that was seized from a Chinese container boat docked in Sydney last year.

Police said the cocaine, hidden inside pre-fabricated steel and which had a street value of $500 million, was the second largest seizure of the drug in Australia.

As the men languished behind bars, Australian Federal Police raided Mr Arnold's home at Murrumbateman, just outside the ACT, and business premises in Goulburn on Wednesday. Officers also searched properties in Jeir and Canberra.

At least one of the other Australians is also believed to have been a prominent businessman who had moved his base to Dubai.

Mr Arnold's defence lawyer, Ben Aulich, on Thursday said: "We're in the process of organising access to see him in Serbia.

"That will be co-ordinated through [the Department of Foreign Affairs and Trade].

"If everything is co-ordinated smoothly and he is not facing charges in Serbia, then we expect him back in the country within four to six weeks."

Mr Aulich declined to comment further.

Related: Director of new Mortlake saleyards arrested

Serbian police released dramatic footage of the arrests that took place in a Belgrade hotel. The footage shows police running through the hotel's doors and pointing their guns at several men sitting in the lobby.

Officers pinned the men to the ground before they handcuffed them, the video showed.

The footage also showed a bag filled with foreign currency. Police said the arrests were made during a "money handover".

Serbian authorities said the arrests had been made in cooperation with Australian police. No one has been arrested in Australia.

Police identified the men by their initials and year of birth as Australian citizens TV (1983), RA (1974), and DK (1969); along with DG (1977), a citizen of Lebanon.

The Lebanese citizen was detained and charged with having forged identity documents.

B92 reported the men were arrested with large amounts of various currencies, including euros, Australian, US and Singaporean dollars, Czech korunas, Vietnamese dong, Japanese yen, Chinese yuan, Thai bahts and Serbian dinars.

They also allegedly had one pistol.

Serbian authorities said they would "continue to cooperate with Australia's authorities in order to implement further action related to this permanent international investigation".

In a statement, the Australian Federal Police said it launched an investigation into an alleged organised crime syndicate after Border Force officials intercepted the shipping container, which had arrived in Sydney via China.

"AFP forensic chemists conducted a deconstruction and analysis of the cocaine and determined a purity of around 78 per cent, meaning the seizure has an estimated street value of up to $500 million," the statement said.

The trio is expected to face charges of conspiracy to import commercial quantities of a controlled drug in the NSW Supreme Court. That offence carries a maximum penalty of life imprisonment.

Related: Saleyard opening not jeopardised by arrest

Mr Arnold's business website said he was born and educated in Canberra. He graduated with a commerce degree in 1995.

He had a 20-year career in the steel manufacturing industry and acted as director of ArnoldCo, Arnold Trading and Arnold Contracting, the website said.

He also worked on regional projects including the South Eastern Livestock Exchange in Yass and the Mortlake Saleyards.

Directors of SELX Pty Ltd, which owns the livestock selling centres at Yass and Mortlake, held an emergency meeting after they learned of Mr Arnold's arrest through media reports.

"The operation and management of [South Eastern Livestock Exchange] and [Western Victoria Livestock Exchange] are not affected by this development," they said in a statement. "Livestock sales will continue as scheduled."

SELX Pty Ltd director Brendan Abbey, whose wife is Yass Valley mayor Rowena Abbey, said he heard about Mr Arnold's arrest on the 6am news and had been in "total shock and disbelief".

He had last spoken to Mr Arnold in Australia on Sunday, when he told Mr Abbey he would be overseas for a short time..

"He has an interest in some steel factories in China and we thought he was going there," Mr Abbey said. "It was a regular thing, [he'd go] every month or six weeks."

He said Mr Arnold was held in "very high esteem" in the community and there had been no signs of any involvement in the alleged drug operation.

"Nothing at all, not a sign of financial stress. Completely out of the blue."

Australian Federal Police's co-ordinator of organised crime and cyber, Detective Superintendent Stephen Dametto, said the worldwide span of the police operation showed how international law enforcement networks to target global crime syndicates.

"This investigation has demonstrated the agility and ingenuity of AFP investigators, who took a seizure and ran with it in cooperation with our international partners to identify an organised crime syndicate," Detective Superintendent Dametto said.

"We know Australia remains one of the most attractive markets for drug imports – in 2017, we made record seizures of cocaine at the Australian border in AFP joint operations.

"We will continue to work cooperatively with our partners to dismantle syndicates behind importations and target their crime networks at their source, wherever in the world that may be."

Australian Border Force's Acting Assistant Commissioner, Strategic Border Command, Tim Fitzgerald, said the seizure was a testament to the detection, intelligence and investigative capabilities of the ABF and partner agencies before, at and after the border.

"This was a sophisticated concealment, but thanks to our highly trained officers and world-class screening technology, we were able to locate the cocaine and ultimately disrupt a significant international drug operation."