Scott Morrison will visit Sri Lanka as the Federal Government continues its silence over a group of Tamil asylum seekers who are believed to have fled the country.

Mr Morrison will fly to the country to attend the commissioning ceremony for the two former Australian Customs patrol vessels gifted to the Sri Lankan government, a spokesman for the Minister said.

Australia announced the gift of two Bay-class patrol boats in November last year, after the vessels saw about 10 years of service with Australian Customs.

They have been brought back to full operational capability at a cost of $2 million and will be used by Sri Lanka to help combat people smuggling in the Indian Ocean.

Mr Morrison’s visit comes as human rights groups raise concerns about the fate of 153 Tamils who have reportedly been intercepted at sea near Christmas Island and handed to Sri Lanka’s navy.

The Tamil Refugee Council said they spoke to a relative of people who were on the boat who said at least 11 of the asylum seekers had been tortured by Sri Lanka’s intelligence services and had a genuine case for protection.

Refugee council spokesman Aran Mylvaganam said there must have been more people on the ship in a similar situation and in need of help from Australia.

The Tamil asylum seekers reportedly fled Sri Lanka to a refugee camp in India before boarding a boat to Australia.

The media last heard that the boat was near Christmas Island when it was intercepted, reportedly by an Australian Customs ship.

For several days the Federal Government has maintained complete secrecy over the alleged operation, refusing to discuss details.

The Government says it does not discuss operational matters in line with its Operation Sovereign Borders policy.

On Friday, Mr Morrison cancelled a public event in Melbourne but Foreign Minister Julie Bishop, speaking from Myanmar, said Australia was abiding by its international obligations.

“We are determined to ensure that our border protection laws have integrity, that we abide by our international obligations, but importantly we stop people making the horrible journey by sea in unseaworthy boats to Australia,” Ms Bishop said on Friday.

“We do not want to see women and children and families drown at sea as happened in the past. We are determined to stop that.”

Sri Lanka has questioned the asylum seekers’ motives.

Sri Lanka High Commissioner Admiral Thisara Samarasinghe has told the ABC that since the ceasefire in 2009 there has been peace in Sri Lanka.

“There is no reason for any Sri Lankan to leave Sri Lanka other than economic opportunities,” he said.

“There have been thousands of failed asylum seekers who have been either voluntarily or involuntarily returned to Sri Lanka.

“They are leading a normal life in Sri Lanka with no harassment.”