戴安娜最后的电话（在线收听）

One more Diana mystery and this time, the questions are for the US government to answer. An official British investigation into Diana's death has found that when she walked through the door of the Ritz Hotel on the last night of her life, she was under surveillance by a US intelligence agency. British newspaper reports now say that on the night she died, Diana was being bugged by the US without the approval of British Security Services. The US has refused to release the files, but investigators say they have been told the highly classified documents shed no new light on her death. In 1998, the National Security Agency disclosed that US intelligence agencies held more than 1000 pages of top secret information on the princess.

It's possible that people she associated with, er, particularly on the landmine issue had become intelligence targets for the United States government.

James Bamford has explored the shadow reward to the NSA. He thinks if Diana was bugged, it was unintentional.

Well I don't think she was in the radar screen, I think she got picked up inadvertently, I think the countries and the people she were meet, she was meeting with were in the radar screen.

It may now become a diplomatic embarrassment, with both the British and the French likely to ask what the US was doing and why. For conspiracies, it's given them one more reason to believe that Diana's death was not an accident. Sheila MacVicar CBS News.