Washington: Six days after former Afghan President Burhanuddin Rabbani was assassinated, authorities in Kabul have arrested a prominent Afghan connected to the Taliban militants as a suspect.

Hamidullah Akhund was arrested "somewhere in Kabul in the past few days", 'New York Times' reported quoting an Afghan Government spokesman Sifatullah Safi.

Few details were released about the suspect and the circumstances of the arrest, the Times said, as Afghan President Hamid Karzai appointed a high level team headed by the defence minister to probe the killing.

"We are getting close to the truth", the spokesman said, as the peace envoy's killing threatens fresh turmoil in the nation as Rabbani supporters are up in arms against continuing peace efforts with the Taliban.

Rabbani, chairman of the Afghan Peace Council was killed by a turban bomber who claimed to be a peace emissary from the Taliban leadership.

Police and other senior figures have blamed the Taliban for the attack, but unusually, the leaders of Afghanistan's ten-year insurgency have so far refused to comment on it.

The investigation will be led by Afghan defence minister Abdul Rahim Wardak, seen as close to Karzai, a statement from the presidential palace said.

A government official said that Akhund had spoken to the bomber a day before the attack. The bomber was believed to be a trusted Taliban emissary, had left the official guesthouse where he was staying to speak to the suspect.

President Karzai and his government have come under intense pressure from political rivals and the Afghan public to arrest whoever was responsible for the plot to assassinate Rabbani.

Rabbani's death last Tuesday was a severe blow to the government's struggle to negotiate peace with the Taliban. It also threatens to open fresh rifts among the country’s ethnic groups.

The killer posed as a Taliban emissary carrying conciliatory messages. He was escorted into Rabbani's heavily guarded home on Tuesday and then set off explosives hidden in his turban as he greeted Rabbani.

Since then, Afghan officials have revealed fragments of a coordinated plot that led the killer, identified as Mullah Esmatullah, toward Rabbani.

They said Akhund was a critical interlocutor between the peace council and Taliban leaders in Quetta, Pakistan, near the Afghan border.

Beginning four months ago, Akhund travelled to Kabul twice to meet with Rabbani and another member of the High Peace Council, Masoom Stanekzai, according to an account given at a news conference this week by Ramatullah Wahidyar, a former Taliban member who now serves on the council.

Akhund recorded an audio message from Rabbani to the Taliban, which he promised to deliver, and passed along reports of his progress and conversations with high-ranking Taliban leaders, Wahidyar said.

About a week ago, he said, Akhund called with news of what seemed like a breakthrough: the Quetta group was ready to talk to the Afghan government, and had an important message to send.

Akhund said he could not go to Kabul personally, but would send a man he trusted, Wahidyar said. The substitute turned out to be the bomber.

(Agencies)