MAIDAN SHAH, Afghanistan: An Afghan army colonel has been arrested by the government for illegally handing over prisoners to a man working with a US special forces team that was accused of torture and killings, three sources have told Reuters.

The rare arrest of a senior military officer underlines the resolve of Kabul in cracking down on excesses in the 12-year-long civil war ahead of an election next year. It also plays into government efforts to distance itself from the West as it woos Taliban insurgents to join peace talks ahead of the withdrawal of international combat troops in 2014.

Reports earlier this year that villagers detained by security forces in the Nerkh district of Wardak province were being tortured or killed led to a serious rupture between Afghan authorities and the US-led multinational force.

Afghan President Hamid Karzai later ordered all Western troops out of Nerkh.

A senior Afghan government official in Kabul and two officials with international organizations said the colonel, who was based in Wardak, had admitted to handing over several prisoners to a man known as Zakeria Kandahari, a shadowy figure who has spent years working with US forces.

All three sources have access to investigations into the case but spoke on condition of anonymity due to the sensitive nature of the subject.

Both Kandahari, who was based in Nerkh, and the US troops there are accused by the Afghan government of committing human rights abuses or complicity.

Kandahari has not been seen in public since early January, according to people in the area and several officials said his name was likely to be an alias. It was not possible to obtain the colonel's name or contact his family or a lawyer representing him.

A senior US military official and the senior Afghan official based in Kabul said Kandahari was working with or for the Americans at the time the prisoners were handed over to him. The senior US official told Reuters Kandahari had no official status with US forces in Wardak.

"This colonel was handing over detainees to Kandahari, thinking that Kandahari worked for the (US) special forces and they had the authority to question any detainee," the Afghan official said.

"This was irresponsible and that's why (the colonel) was himself detained and is being investigated," he said.

When asked, spokesmen and officials at the Afghan ministry of defence and the national directorate of security, the country's main intelligence agency, said they could not confirm the colonel's arrest.

US Lieutenant Colonel Tom Bryant, a spokesman for a multinational special forces command in Afghanistan, refused to comment directly on the arrest of the Afghan army colonel. A spokesman for the NATO-led International Security Assistance Force (ISAF) in Afghanistan, to which the special forces unit in Nerkh did not report, also refused comment.