BAGHDAD — The closure of a Baghdad detention facility at the centre of torture allegations is insufficient and authorities must probe and prosecute anyone implicated in the abuse, Human Rights Watch said on Thursday.

"Closing torture prison won't end abuse," the New York-based rights watchdog headlined a statement referring to a declaration this month by Iraqi authorities that Camp Honor had been shut down.

The decision was a "positive move but only a first step," HRW said.

"Iraqi officials should establish an independent body with authority to impartially investigate the torture that occurred at Camp Honor and other sites run by" security services connected to the office of Prime Minister Nuri al-Maliki.

"The investigating body should recommend disciplinary steps or criminal prosecution of everyone of any rank implicated in the abuse," it said.

Earlier this month, Iraq's Justice Minister Hassan al-Shammari announced the closure of a prison in Baghdad's heavily fortified Green Zone, due to inconsistencies in human rights standards at the facility.

The Los Angeles Times reported in January that prisoners were kept under harsh conditions at Camp Honor, sometimes for up to two years.

Former detainees at the facility had told HRW that "interrogators beat them, hung them upside down for hours at a time, administered electric shocks to various body parts, including their genitals, and asphyxiated them repeatedly with plastic bags put over their heads until they passed out," the statement said.