WikiLeaks publisher Julian Assange has been an ''irritant'' and ''a gadfly'' but not a significant security threat, according to former Australian intelligence and security officials.

Former government officials say only one of the 1400 US diplomatic cables relating to Australia published by WikiLeaks caused any major security concern, and no one was harmed as a consequence.

Julian Assange. Credit:Nick Miller

This relatively relaxed view of Mr Assange undercuts assertions by former prime minister Julia Gillard who said that WikiLeaks' release of leaked cables was ''a grossly irresponsible thing to do, and an illegal thing to do.''

Former security and intelligence officers say that while WikiLeaks' disclosures in 2010 and 2011 were embarrassing to the government ''no great harm was done''. ''Assange proved more an irritant or a gadfly than anything else,'' one former intelligence officer said. By comparison former US intelligence contractor Edward Snowden's leaks are considered to be ''much, much more damaging''.