According to the Wikileaks private message trail it is claimed that Hanley has published a detailed online diary of her travels to Europe last year, which included attending several neo-Nazi skinhead gatherings, visiting Adolf Hitler's birthplace, placing flowers on his parents' grave and collecting Nazi memorabilia. "Hearing/joining in with so many hundreds of people chanting Sieg Heil together is something that will stay with me forever," she allegedly wrote.

The online messages allegedly reveal that Hanley has also hosted international Blood & Honour activists at her house in Canberra and dated several neo-Nazi skinheads. Blood & Honour, which promotes neo-Nazi music and events, was founded in Britain in 1987 and has been outlawed in Germany and Spain. Its Australian chapter is organising a pro-Hitler gig in Perth for Anzac Day. In one of her online messages, Hanley is reported as saying that she would like to become "more active in supporting B&H Australia".

"I think that with my skills and background I would have a lot to offer," she wrote. "Nothing would make me happier than to see B&H Australia become stronger and larger. I would also love to see the skinhead scene in Australia return back to the size and strength of the glory days."

Even though the Department of Defence conducted background checks on all Thales contractors, claims about Hanley's links with neo-Nazi skinhead groups were unknown to Thales or the department until smh.com.au provided copies of the private messages. Thales immediately began an investigation and suspended Hanley, who is in her 40s, saying it took security "extremely seriously". It said the matter had been referred to "appropriate authorities for further investigation".

"The person in question was a contractor engaged through an employment agency," a Thales spokeswoman said. "The contract has been suspended and all access to Thales IT and equipment removed."

The Department of Defence said it could not comment on security allegations relating to specific people, but would have concerns about employees known to have links with nationalist extremist or racial organisations. It would not comment on Hanley's security clearance level. In another message attributed to her she discussed how she listened to a white supremacist online radio show. Reached at her home on Friday and this morning, Hanley refused to comment on the allegations and threatened legal action over any future reports based on the material published by Wikileaks.

"I'm under legal advice not to speak to you," she said, before hanging up. Thales, which refused to give any further details about the investigations or about Hanley, generates about $1 billion in revenues annually and specialises in high technology defence products such as electronic warfare, munitions and protected mobility vehicles.

Mat Henderson, a volunteer with Australian anti-racism group Fight dem back, said bad economic times were always a fertile recruitment ground for racist groups.