Islamabad, Jan 28 : United Nations Secretary General Ban Ki Moon is expected to announce a commission to investigate the assassination of former Pakistan Prime Minister Benazir Bhutto when he visits Islamabad on February 4.

"Secretary General Moon would announce the commission during his forthcoming visit to Pakistan," the Dawn quoted a senior diplomatic source, as saying.

The UN had few weeks back proposed to Pakistan the terms of reference for instituting an independent inquiry commission into the circumstance of the killing of Bhutto.

Foreign Office Spokesman Muhammad Sadiq had earlier said that the UN was in an advanced stage of instituting the inquiry.

Pakistan had in June 2008 requested for the probe calling upon the UN to constitute a commission to expose through independent and impartial investigations the culprits, perpetrators, financiers and mastermind behind the December 27 assassination of former Prime Minister Bhutto after a political rally in Rawalpindi.

The Pakistan Government said that it was seeking an international probe because it suspected an international conspiracy behind the assassination of the PPP leader.

It further said that investigating an international conspiracy was beyond the capacity of the local investigators.

Later in July 2008, Foreign Minister Qureshi visited UN Headquarters to discuss with the Secretary General Moon Pakistan's request for the investigation.

On that occasion a broad understanding was reached on such issues as the nature of the Commission, funding modalities, composition, unhindered access to all sources of relevant information, and elements to safeguard its objectivity, impartiality and independence.

However, discussions within the UN and between UN and Pakistan government continued examining other modalities and the Commission''s structure, including the scope and mandate. (ANI)