Islamabad: Pakistan rejected Afghan accusations that it had refused to cooperate in the investigation into the assassination of Kabul government peace envoy Burhanuddin Rabbani.

"We completely reject, this is not true," said foreign ministry spokeswoman Tehmina Janjua.

"Pakistan stands by its commitment to help Afghanistan in investigating Mr Rabbani's killings," she said.

Earlier Afghanistan's deputy head of National Directorate of Security intelligence agency Mohammad Yasin Zia said: "We received a message from the embassy of Pakistan saying that since this issue has arisen in media, we cannot cooperate and we apologise for that."

Janjua said she had talked to Pakistani ambassador Mohammad Sadiq in Kabul who also denied the allegations.

"I myself spoke to our ambassador in Kabul who said ‘This is not correct. We have not said this'," she added.

She said Prime Minister Yousuf Raza Gilani had himself offered cooperation in the investigation, when he visited Kabul to express his condolences over the assassination.