Visa bribe claims sent to corruption probe

Claims a convicted New Zealand drug trafficker bribed his way out of being deported from Australia have been referred to a federal anti-corruption agency.

William Sualauvi Betham allegedly bragged to a fellow detainee in immigration detention on Christmas island he could pay $80,000 to a "certain person" in Brisbane to get a visa within months.

Home Affairs secretary Michael Pezzullo said the matter has been referred to the Australian Commission for Law Enforcement Integrity.

He stressed there was a low threshold for referral because his department was not the investigating authority.

"It would be remiss of me not to draw that to the commissioner's attention," he told a Senate estimates hearing in Canberra on Friday.

"In effect, I've referred an allegation to the commissioner."

Betham is living on the Gold Coast after a decision to cancel his visa was overturned despite his conviction over involvement in a drug trafficking syndicate.

Home Affairs Minister Peter Dutton last month strenuously dismissed the bribery claims, saying the report relied on a spurious account.

"Do you find it extraordinary that a matter you referred to ACLEI was rejected as entirely false by a minister?" Greens senator Nick McKim asked Mr Pezzullo, before the question was ruled out of order.

Mr Pezzullo said he had no evidence before him that any departmental official had engaged in misconduct.

"We're not going to pre-determine an outcome, but equally we're not going to sweep anything like this under the carpet," he said.