UNITED NATIONS - The independent commission investigating the assassination of former Prime Minister Benazir Bhutto is satisfied with the cooperation being extended by the Pakistani government, and rejected reports it was denied access to certain personalties, a UN spokesman said Tuesday. "There were no restrictions on the team's access," Spokesman Martin Nesirky said in response to a question at the regular noon briefing. "They (the investigating team members) say that they are pleased by the cooperation of the Pakistani authirities," he added. Last week Naheed Khan, Ms. Bhuttos political secretary, had criticized the government for allegedly denying the UN team access to certain personalities. As regards the three-month extension sought by the three-member commission for completing its probe, the spokesman said the security situation in Pakistan was indeed complex, but he has nothing specific on it. The commission, which began its work on July 1, was mandated to submit its report to Secretary-General Ban Ki-moon by December 31, 2009. But the commission has said its needed more time -- till March 31, 2010 -- since its work schedule was affected by the security situation in Pakistan. Last month, Chile's UN Ambassador Heraldo Munoz, who heads the commission, had hinted about the delay in submitting the report. "We're working hard and advancing, but there is a great deal of work to be done," he had told reporters, while also citing the security situation in Pakistan in contributing to the delay. Meanwhile, an advance team of the commission will leave for Pakistan on Dec. 10 to be followed by other members tentatively the following day. During the upcoming trip, the commission will interview PML-N Quaid Nawaz Sharif, Chief Justice Iftikhar Muhammad Chaudhry, President Asif Ali Zardari and Interior Minister Rehman Malik, according to informed sources. It has already interviewed former President Pervez Musharraf. The Commission of Inquiry has held meetings with a range of Pakistani citizens, diverse political party leaders and Government officials, and also gathered additional materials relevant to the inquiry. During its previous visit in July, the commission visited Rawalpindi where the Ms. Bhutto was killed and held meetings with top officials. The other members of the commission are: Marzuki Darusman, the former attorney-general of Indonesia, and Peter Fitzgerald, a veteran of the Irish National Police who has also served the UN in a number of capacities.