The creators of Australian Internet hit Rap News on Wednesday said they were still "pinching themselves" after controversial and reclusive WikiLeaks founder Julian Assange appeared in a cameo role.

University researcher Giordano Nanni and English teacher Hugo Farrant, whose political satire set to hip hop has achieved cult status on YouTube, said Assange contacted them and invited them to London to film the six-minute skit.

Rap News episode five, titled News World Order: War on Journalism was made in October, ahead of Assange's leak of almost 400,000 secret logs from the Iraq War, and deals with the implications of the release.

The Melbourne-based pair had made a previous episode about WikiLeaks and told AFP via e-mail: "He really felt that we'd nailed it, so the possibility of going to London and collaborating on a new episode in the lead-up to the Iraq War Diaries was mooted. "We jumped at the chance and were on planes within a fortnight."

Once there, Farrant said it seemed logical to offer Assange a role in their parody and, despite some initial raised eyebrows, the WikiLeaks boss was "totally up for it".

It took several takes ("not as many as you'd expect") but Assange managed to get the rhythm down and chime in with the rap performed by Farrant.

"He was full of creative ideas for how to act and time the entrance, and he really enjoyed lampooning his own image," Farrant said.

"It was fantastic - we're still pinching ourselves," added Nanni. "He's a preternaturally calm person, but with a great sense of humor."

Despite his "incredibly hectic schedule" - including the leaking of a huge cache of American diplomatic cables and being arrested over alleged sex crimes in Sweden - Farrant and Nanni said Assange kept in touch, with an "occasional message shooting through the ether".

"It means a lot, of course," the pair said.

"Our intention with this project was to provide a meaningful contribution to the media discourse around certain issues, so to get access to such an influential figure ... was very gratifying indeed."

A number of Rap News episodes deal with WikiLeaks and parody figures including United States Secretary of State Hillary Clinton, Libyan leader Moamer Kadhafi and Italian Prime Minister Silvio Berlusconi, all played by Farrant.