"Deserved a medal" ... Nick Xenophon with Allan Kessing.

"Deserved a medal" ... Nick Xenophon with Allan Kessing. Photo: Peter Rae

Customs was warned 10 years ago of gaping holes in its security and the potential for corruption to thrive among its ranks in a report that was ignored by authorities at the time, according to Independent Senator Nick Xenophon.

Former customs officer Allan Kessing was commissioned by his superiors to write two security reports, in 2002 and 2003, which detailed major problems at Sydney Airport, including up to 20 per cent of staff working in airport sterile areas with criminal convictions and others who were living in Australia illegally, Mr Xenophon said.

Airport

Customs is investigating criminal allegations involving its staff.

The reports also revealed a concern about the possibility of terrorists infiltrating staff ranks at Sydney Airport, Mr Kessing said.

But Mr Kessing on Friday said he and other customs staff were "dumbfounded" when the manager of airport security for customs at the time rejected those reports for being financially and "commercially too onerous" on the airport, Qantas and other major airport operators.

He claimed that if action had been taken at the time he finalised his reports, this week's revelations that Australian Customs and Border Protection staff had been involved in alleged corruption and drug trafficking could have been avoided.

Mr Xenophon said Mr Kessing "deserved a medal" for writing the reports and speaking publicly about their findings on Friday, which he did at the risk of prosecution.

"These reports were deliberately suppressed by customs back in 2003," Mr Xenophon said.

He said if Mr Kessing's reports had been acted on, "we would not have had the problems we are now seeing within customs".

"You have to ask the question: how many Australians have overdosed on narcotics as a result of corrupt customs officials allowing these drugs into Australia?"

Mr Kessing said in April 2005 he approached Anthony Albanese, the then-opposition transport spokesman, and briefed one of his staffers about his concerns surrounding the reports, before meeting personally with Mr Albanese.

Information contained in Mr Kessing's reports appeared in The Australian newspaper a few months later.

Mr Kessing claims he then was the subject of a witch hunt. His home and that of his recently deceased mother were raided in 2005, and the Australian Federal Police spent $250,000 tapping his phones and putting him under surveillance, he said.

In 2007 Mr Kessing was convicted for breaching Section 70 of the crimes act, but denies he supplied The Australian with the report.

Mr Xenophon said in the wake of this week's revelations about alleged corruption and criminal activity at Sydney Airport, Mr Kessing should be pardoned and his two reports publicly released.

"The scandal is that this man who deserves a medal for the work he did 10 years ago was actually persecuted through the courts, had his life effectively ruined," Mr Xenophon said.