The chief prosecutor of the UN-backed special court probing the 2005 murder of former Lebanese president Rafiq Hariri announced Wednesday that he will leave the post when his term ends in February.

"Daniel Bellemare has informed the Secretary-General of the United Nations that, for health reasons, he does not intend to seek reappointment for a second term as prosecutor at the end of February 2012," the Special Tribunal for Lebanon (STL) said in a statement.

"While this long and difficult journey is far from over, solid foundations have been laid to achieve justice and accountability for the attack of 14 February 2005 and connected cases, through the rule of law," Bellemare added in the same statement.

The Canadian-born lawman was appointed chief prosecutor to The Hague-based tribunal in March 2009, after previously serving on the UN's commission to investigate the attack on Hariri on February 14, 2005.

On that day, the former Lebanese politician and 22 others including a suicide bomber died in a massive car bomb blast in Beirut.

Arrest warrants for four operatives, members of the Iranian-backed Hezbollah Shiite militia, have been issued by the court, but so far they have not yet been arrested.

The STL's former president, Italian judge Antonio Cassese died of cancer in October, days after stepping down from the post.