TORONTO - NDP leader Jack Layton is calling on the federal Conservatives to take immediate action to secure the release of a Canadian-Iranian journalist held in Iran since June.

Layton is holding a news conference this morning at the downtown Toronto home of Maziar Bahari.

Bahari, who is a correspondent for Newsweek, was one of at least 24 journalists and bloggers arrested in the aftermath of Iran's disputed election.

The U.S. publication has said Bahari was "detained without charge" by Iranian authorities in Tehran on June 21.

Bahari was born in Iran and had studied at Montreal's Concordia University before becoming a Newsweek correspondent.

Foreign Affairs Minister Lawrence Cannon lodged a protest with the Iranian Embassy two weeks after Bahari was detained - a delay Layton is calling "unconscionable."