Australia would have stooped to a “new low” if reports its navy paid people-smugglers bound for Australia thousands of dollars to turn back their boat are true, an Indonesian government official has said.

A boat captain and two crew members arrested this week on suspicion of human trafficking told Indonesian police that Australian authorities had paid each of them $US5,000 ($A6450) to turn back their vessel with 65 migrants on board.

“Under Australian’s push-back policy we have been consistently saying they are on a slippery slope,” Indonesian foreign ministry spokesman Armanatha Nasir said.

“Should this situation be confirmed and it turns out to be true, it would be a new low for the way the government of Australia handles the situation on irregular migration.”

Nasir said it would be the first time such an incident occurred involving Australian authorities.

Indonesian foreign minister Retno Marsudi raised the issue with Australia’s ambassador to Indonesia, Paul Grigson, on the sidelines of a foreign policy conference in the Indonesian capital, Jakarta.

“He promised to bring my question to Canberra,” Marsudi told reporters. “We are really concerned, if it is confirmed.”

Indonesia plans to ask Australia for clarification, he said.

Australian authorities could be accused of people smuggling over the issue, an international law expert says.

The prime minister, Tony Abbott, did not deny the claims when questioned about it on Friday.

Professor of international law at the Australian National University, Don Rothwell, says if proven the activity could be tantamount to people smuggling under current regional protocols.

“People smuggling is defined with the protocol and to that end the provision of monies to people who are engaged in people-smuggling activities to take persons from a place on the high seas to another place, such as Indonesia, is clearly a people smuggling-type activity,” he told the ABC.