The captain of a merchant ship bound for Singapore changed course for Australia this week, fearing that desperate asylum seekers he had rescued in Indonesian waters posed a threat to his crew, officials said Thursday.

News of the high seas drama broke as Australia's Senate was due to pass strict new laws Thursday aimed at deterring the waves of asylum seekers from across Asia and the Middle East who have been making the dangerous journey to Australian shores.

One of the asylum seekers fell overboard before the rescue and is believed to have drowned, while the surviving 67 have been in an Australian immigration detention center since Tuesday, Home Affairs Minister Jason Clare said.

Clare said they could be deported to tent camps in the Pacific countries of Nauru or Papua New Guinea under the new law. The opposition has called for the asylum seekers, all men, to be charged with piracy for using threats to divert the 265-meter (870-foot) ship.

What exactly happened on the ship remains unclear, but accounts of the incident show the captain felt the situation could grow dangerous and pose a threat to his crew if he didn't divert.

Wallenius Marine, the Singapore-based operator of the rescue ship MV Parsifal, said the men were 71 kilometers (44 miles) south of the main Indonesian island of Java in a crowded fishing boat headed for the Australian territory of Christmas Island, 400 kilometers (250 miles) to the south, when they made a distress call to Australian rescue authorities Tuesday morning.

Australian authorities alerted all merchant shipping in the area, and the Parsifal, a Singapore-flagged Swedish-owned car carrier, was the first to respond.

Having fulfilled his obligation under maritime law to rescue the asylum seekers, the captain ordered his crew to continue to Singapore, the ship's intended destination.

"When the asylum seekers on the boat found out about this, they became very aggressive and the master of the ship made the decision to turn the vessel around and head to Christmas Island," Clare told Australian Broadcasting Corp. radio.

Claire said the captain, who has not been named, radioed authorities to tell them "he was concerned for his crew's safety." Australian authorities provided a navy patrol boat escort at the captain's request.

Wallenius Marine said in its statement that the men had threatened to harm themselves, but "there was no physical aggression."

Clare said he did not have details of the behavior of the asylum seekers, reported by The West Australian newspaper to be from the Middle East.

The asylum seekers were delivered to the immigration detention center on Christmas Island late Tuesday, hours after the government warned that any new boat arrivals could be sent to Nauru, a tiny atoll, or an island off Papua New Guinea, Australia's nearest neighbor, to have their refugee claims assessed.

The minor Greens party has condemned the plan as cruel.

The Australian Federal Police said in a statement they had had spoken to the captain who "did not wish to pursue this matter at this time." Police were continuing to investigate.

The merchant ship was headed to Singapore on Thursday and the captain was not available for comment, the ship's operator said.

Military reconnaissance teams were to fly to Papua New Guinea on Thursday and Nauru on Friday to plan the new detention camps. The first asylum seekers are to be sent to Nauru within a month.

More than 7,600 asylum seekers - many from war-torn countries, including Afghanistan, Iraq and Sri Lanka - have reached Christmas Island in more than 100 boats so far this year.