Two Australian ambassadors knew about Wyatt Roy's intention to travel to Iraq but they did not tell headquarters in Canberra, which learnt about it weeks later in the media.
The former Liberal MP in late September was caught in crossfire between Islamic State fighters and Kurdish Peshmerga forces near an area Australians are legally banned from visiting.
A Senate committee on Thursday was told Mr Roy informed Australia's ambassador to Israel Dave Sharma about his desire to travel to Iraq and the Kurdish region during a dinner on September 14.
Mr Sharma warned Mr Roy about the dangers and the government's travel advice.
Department officials emphasised that Mr Roy had not been "definitive" about his travel plans during the conversations.
The ambassador in Baghdad Christopher Langman was also informed in an email by Mr Sharma that Mr Roy was considering travel to Iraq.
The hearing was told an associate of Mr Roy had phoned the embassy in Baghdad on September 20 and spoke to the deputy head of mission seeking help setting up meetings in Erbil, the capital of Iraqi Kurdistan.
The embassy did not offer any assistance.
Foreign affairs department officials were unsure whether Mr Roy had been formally debriefed about his adventures to the war zone and took the question on notice.
Mr Roy lost his federal Queensland seat of Longman at the July 2 election.
