Bilawal Bhutto Zardari (r) and his father Asif Ali Zardari in Naudero near Larkana, Pakistan, 30 Dec 2007

The husband of slain Pakistani opposition leader and former prime minister Benazir Bhutto has again called for a United Nations investigation into her death.

In an opinion piece published in The Washington Post newspaper Saturday, Asif Ali Zardari said a probe conducted by Pakistan's government will have no credibility. As he put it, "one does not put the fox in charge of the henhouse."

Zardari also urged the United States and Britain to support his call for a U.N. investigation.

A team of British anti-terror officers from Scotland Yard examined the scene of the attack on Ms. Bhutto in Rawalpindi Saturday. Ms. Bhutto was killed December 27 in a gun and suicide bomb attack after an election rally, and much of the blood and debris was washed away soon after her killing.

The British officers are in Pakistan to provide technical and forensic assistance to the government's investigation of the assassination, at the request of Pakistani President Pervez Musharraf.

Mr. Musharraf blames Islamic extremists for the assassination, and he has denied accusations that the country's military and intelligence services were involved.

Controversy surrounds Ms. Bhutto's death, with the government alleging that she died when she hit her head during the suicide bombing. Her supporters in the Pakistan People's Party contend she died from a gunshot to the head.

The European Union is preparing to launch a monitoring mission ahead of Pakistan's February 18th parliamentary elections. EU officials say a core team of 11 experts will be joined by at least 50 long-term observers to monitor the election process.

Some information for this report was provided by AFP and AP.