Benazir Bhutto's son on Tuesday called for a U.N. sponsored investigation of her murder, saying that he does not trust officials in Pakistan.

"We do not believe that an investigation under the authority of the Pakistani government has the necessary transparency," Bilawal Bhutto Zardari told a news conference. "Already so much forensic evidence has been destroyed."

The 19-year-old Oxford University student was chosen to succeed his mother as leader of the Pakistan People's Party, though day-to-day leadership is in the hands of his father, Asif Ali Zardari.

"It was recognized at this moment of crisis that the party needed a close association with my mother through the blood line," said Bilawal Bhutto Zardari.

"Also it was important to give hope to the new generation of Pakistanis who are looking not just to these elections but beyond."

Zardari pleaded for privacy as he pursues his studies at Oxford, where he is in his first year.

"Politics is also in my blood, and although I admit that my experience to date is limited, I intend to learn," he said.

"However, my immediate priority is to return to Oxford to continue my studies. Unless I can finish my education and develop enough maturity I recognize that I will never be in a position to have sufficient wisdom to enter the political arena."