Mr Canavan’s resignation follows the departure of two other MPs – Larissa Waters and Scott Ludlam – who hold dual citizenships with Canada and New Zealand respectively.
“I had no knowledge that I had become an Italian citizen, nor had I requested to become an Italian citizen,” Mr Canavan said.
“In the short time available I have not been able to obtain legal advice as to whether my registration as an Italian citizen, without my knowledge, was valid under Italian law.”
Attorney-General George Brandis has said that the preliminary view of the government is that, as the citizenship was obtained without Mr Canavan’s knowledge, he may not be in breach of Section 44 of the constitution, which disqualifies dual or plural citizens from election.
The matter is being referred to the High Court and a decision will be made when Parliament returns.
Deputy Prime Minister Barnaby Joyce will take over Mr Canavan’s portfolios and responsibilities within the cabinet until a decision is made.
Watch Mr Canavan’s resignation on ABC news.
