Sri Lankan asylum-seekers who were sent back by Australia cover their faces as they wait to enter a magistrate's court in the southern port district of Galle. Picture: Stringer

Colombo -

Australia's immigration minister reacted angrily on Wednesday to claims by Sri Lankan migrants that they were abused and mistreated by Australian officials while being forced home in a controversial mid-sea operation.

Attending a ceremony in Colombo harbour, Scott Morrison said the claims by some of the 41 returned asylum-seekers were offensive.

“I find those allegations offensive and reject them absolutely,” Morrison told reporters after the ceremony with President Mahinda Rajapakse to commission two boats donated by Australia to combat people-smuggling.

He dismissed rights groups' concerns that the migrants could be mistreated after being sent back to Sri Lanka. “We don't have those concerns, based on the assurances (from Colombo) to the previous (Australian) government,” he said.

Some of the migrants, who included four women and nine children, claimed on Tuesday that they were locked up, given little food and treated “worse than dogs” by Australian authorities mid-sea after their boat was seized.

Some claimed they were racially abused, denied medication and given out of date food by customs officers. Several said they had been trying to get to New Zealand to find jobs.

The group appeared in a court in the town of Galle on Tuesday charged with illegally leaving the country, after spending the night in a Sri Lankan high-security detention centre upon their return.

While the children were discharged, the rest of the group face an initial charge of breaking immigration law, which carries a maximum penalty of two years in jail.

Most are members of Sri Lanka's majority Sinhalese community rather than minority Tamils - some of whose members have suffered persecution since the end in 2009 of a decades-long separatist war.

Australia has come under fire over the transfer, with experts saying its shipboard screening to determine whether the migrants had refugee status appeared inadequate under international law.

Morrison declined comment on the fate of another 153 Sri Lankans being held in custody on the high seas, saying the matter was still before the courts.

Australia faces growing pressure over its immigration policies with High Court action under way over the 153, who are currently detained on a customs boat.

Lawyers argue that any transfer back to Colombo would be illegal, with concerns about the way they were screened.

A Sri Lankan navy source said Colombo may not accept back the group because their boat was thought to have left for Australia from southern India, close to Sri Lanka.

“Our information is that the boat with 153 people had left Indian shores and we are not sure (of) the identity of the people onboard,” the source said, asking not to be named.

“That is why we don't want to take them back like the group of 41 people who had set out from our east coast.”

Morrison said Australia and Sri Lanka were working closely to stop people smuggling.

“The recent return of a group of 41 Sri Lankan nationals who attempted to arrive illegally by boat to Australia serves as a testament to this relationship,” Morrison said in a statement after the ceremony.

Australia's conservative Prime Minister Tony Abbott came to power in September vowing to stop the flood of asylum-seekers arriving on rickety boats, mainly from Southeast Asia, with hundreds of people dying en route.

Morrison told reporters Australia's illegal immigration policy was successful and no people-smuggling boats had arrived for nearly seven months. - Sapa-AFP