The former head of Australia's Border Force is still under investigation for corruption despite being sacked more than three months ago.

Roman Quaedvlieg was one of Australia's highest-paid public servants until his unprecedented dismissal for helping his girlfriend land a job with the agency.

The termination came after inquiries were launched by the Prime Minister's Department and the Australian Commission for Law Enforcement Integrity (ACLEI).

The ABC has now learned the ACLEI probe is still underway — more than a year after the Commonwealth watchdog was told of Mr Quaedvlieg's alleged misconduct.

"I've never been interviewed by anyone, including ACLEI," Mr Quaedvlieg said in a statement.

"This is the first I've heard the ACLEI investigation is still active."

Fall of Roman's empire: May 2017: Roman Quaedvlieg begins paid leave following complaint

May 2017: Roman Quaedvlieg begins paid leave following complaint June 2017: Australian Commission for Law Enforcement Integrity (ACLEI) notified

June 2017: Australian Commission for Law Enforcement Integrity (ACLEI) notified August 2017: ACLEI provides update to Immigration Department boss

August 2017: ACLEI provides update to Immigration Department boss August 2017: PM's Department boss asked whether grounds exist to sack Quaedvlieg

August 2017: PM's Department boss asked whether grounds exist to sack Quaedvlieg February 2018: Attorney-General receives PM's Department report

February 2018: Attorney-General receives PM's Department report March 15, 2018: Governor-General terminates Quaedvlieg's employment

The inaugural Border Force commissioner said he was considering his legal options after being removed from the $600,000-a-year role.

"My position has not changed — I deny the allegations," he said.

"I'm frustrated at the time the entire process has taken."

The commission said it received a referral from Immigration Department secretary Michael Pezzullo mid-last year.

"The Integrity Commissioner received a notification in relation to Mr Quaedvlieg … in June 2017 and commenced a corruption investigation shortly thereafter," a spokesman said.

"At this time the investigation remains ongoing."

ACLEI has oversight of about 20,000 Commonwealth law enforcement officials, including members of the Australian Federal Police and the Home Affairs Department.

The agency had 47 full-time-equivalent staff during the 2016-17 financial year.

Attorney-General yet to receive investigation's final report

Governor-General Peter Cosgrove ended Mr Quaedvlieg's employment in March this year.

The Federal Government said the former border boss:

Interfered to help his girlfriend get a job

Interfered to help his girlfriend get a job Misled Immigration Minister Peter Dutton about the relationship

Misled Immigration Minister Peter Dutton about the relationship Did not reveal the relationship when the woman applied to work for Border Force

Did not reveal the relationship when the woman applied to work for Border Force Did not properly disclose his relationship to the government agency in charge of security clearances

Mr Quaedvlieg was previously the chief police officer in the ACT and a senior official with the Australian Crime Commission.

The ACLEI spokesman said an investigation remained ongoing until a final report was provided to the Attorney-General and the relevant law-enforcement agency.

"The Attorney-General has not received a final report from the Australian Commission for Law Enforcement Integrity in relation to this matter," a spokesman for Christian Porter said.

Federal Labor Leader Bill Shorten said the investigation into the former Border Force boss highlighted the need for a federal anti-corruption body.

"With all respect to the people doing the investigation, why don't we have a national anti-corruption commission?" he asked.

"It just shows you how stubborn [Prime Minister Malcolm] Turnbull and the Government are by their stubborn resistance to have an anti-corruption commission at the national level."