Eighteen Sri Lankan male asylum seekers have been sent home after refusing to be transferred to the offshore processing centre on Nauru, Australian Immigration Minister Chris Bowen says.

Bowen said the Sri Lankans left Christmas Island for Colombo today after asking to be sent home instead of being sent to the Pacific island for the processing of their claims as asylum seekers.

The first group to be sent for offshore processing since new asylum seeker laws were enacted were transferred from Christmas Island to Nauru on September 14.

Australia has reopened the processing centre at Nauru and is soon to reopen Papua New Guinea's Manus Island as part of the federal government's policy to stem the number of boat arrivals.

Bowen also said the government would introduce a recommendation from the Houston independent panel to bar people arriving by boat from sponsoring family under the Special Humanitarian Program.

The Houston report on asylum seeker policy, handed to the government on August 13, recommended 22 key measures to stem the boat arrivals to Australia. Bowen said the plane carrying the 18 men left Christmas Island bound for the Sri Lankan capital.

He said 16 of the 18 men arrived in Australia after August 13, when the government announced its new border protection policies.

"They have asked not be transferred to Nauru, but instead to be returned to their homeland of Sri Lanka," Bowen told reporters in Sydney.

"That has been arranged and facilitated." Bowen said the government's move exposed the lie of the rhetoric from people smugglers in offering a passage to Australia.

"These people have been misled by people smugglers to believe that a visa would be available on their arrival in Australia," he said.

"What this transfer does, and together with the transfer to Nauru over the last week, show is that if you come to Australia by boat, you risk your life and you throw your money away."

The minister said the changes to the concessions under the special humanitarian programme would ensure family reunions occurred only through the normal channels.

"There will be no special concessions," Bowen said.

"Up until now it had been possible for people who arrive in Australia by boat to sponsor family members and not to show that the other requirements under the special humanitarian program were met."

Bowen said the government had also accepted the recommendation to increase the numbers of people accepted under the family reunion program by 4000.

- AAP