TEHRAN // Iranian police late on Monday arrested the former Tehran prosecutor Saeed Mortazavi, an ally of President Mahmoud Ahmadinejad.
Mr Mortazavi, Tehran's notorious former prosecutor, was suspended in August 2010 along with two other judges over the death in prison of three anti-government protesters in the aftermath of the 2009 presidential election.
A parliamentary investigation found Mr Mortazavi responsible for sending protesters to Kahrizak, a detention centre south of Tehran, and demanded that he be punished.
He was at the centre of a raucous parliamentary session on Sunday when the bad blood between Iran's government and parliament spilt into open.
A majority of MPs voted in a heated parliament session, broadcast live on state radio, to remove the labour and social welfare minister, Abdolreza Sheikholeslam, for refusing to sack Mr Mortazavi.
Mr Mortazavi, seen close to Mr Ahmadinejad, had been appointed as caretaker of Iran's wealthy social welfare organisation.
Sunday's brawl came as Iran gears up for its presidential election on June 14 to find a replacement for Mr Ahmadinejad, whose victory in 2009 sparked protests against poll results which the opposition claimed were rigged.
The rift between Mr Ahmadinejad and parliament, dominated by conservatives critical of his administration, first surfaced in April 2011 after he challenged a ruling by supreme leader Ayatollah Ali Khamenei, who has final say on all state matters.
The dismissal of Mr Sheikholeslam on Sunday marked parliament's second successful unseating of Mr Ahmadinejad's ministers in his second and last term. In February 2011 the then transport minister was dismissed.
During Sunday's feisty debate, Mr Ahmadinejad accused the parliament speaker, Ali Larijani, and the judiciary chief, Ayatollah Sadegh Larijani, of nepotism.
To back his claim, the president played a recording in which a voice said to be of their brother, Fazel, allegedly attempts to bribe Mr Mortazavi by asking for a favour in exchange for political support of both parliament and the judiciary.