Princess Diana was killed in a road accident in 1997 after attempts to frighten her into dumping her boyfriend Dodi al Fayed and ending her anti-establishment activities went horribly wrong,a leading British lawyer has claimed. Lawyer Michael Mansfield,who represented Dodis father Mohamed al Fayed at the 2007 inquest into Dianas death,said he was sure that Dianas killers had no intention of ending her life and simply wanted to scare her. Mansfield believes there was a plan to frighten her which went horribly wrong in a Paris tunnel in August 1997,the Daily Mail reported. I dont believe anyone wanted to see her dead. I think there was a plan to sabotage the relationship (with Dodi) and alter her life,to try to stop her activities. But this plan went very badly and ended with her death, Mansfield said. In an interview with Catalan daily El Periodico published today,Mansfield said British authorities opposed several aspects of Dianas private and public life. He said: I believe the relationship between Princess Diana and Dodi al Fayed displeased the authorities. In spite of all the work Mohamed al Fayed did for children and hospitals,he was persona non grata in Britain. As far as Diana was concerned,she had given interviews attacking the Royal Family for the way they treated her,but I think what most annoyed the authorities was that Diana became very actively involved in the campaign against land mines. Mansfield,the radical Queens Counsel (QC),said: The investigation into Dianas death showed she was preparing to denounce British complicity in the sale of weapons to countries that do not respect human rights. He said: Dianas fears for her safety and her reoccupation with surveillance were thoroughly canvassed,and in my view were found to be entirely justified. Unfortunately her predictions came to pass. His latest comments on the tragedy were made during a trip to Barcelona. Earlier in memoirs published last year on his colourful 40-year career,Mansfield has claimed that Dianas road crash death was no accident. He has said: In case of Diana and Dodi,I have always believed that whatever had caused the crash,it was not an accident. As it transpired,that belief was shared by the jury at the inquest. A jury,after a six-month inquest at the Royal Courts of Justice,concluded in April 2008 that Diana had been unlawfully killed. It blamed the grossly negligent driving of her chauffeur Henri Paul and chasing paparazzi photographers. However,Mohamed al Fayed,who told the inquest Diana was murdered in a conspiracy involving Tony Blair,MI5,MI6 and the British ambassador to France,has always refused to accept the verdict.