Princess Diana died as an attempt to scare her to leave her lover Dodi Fayed went terribly wrong, a lawyer has said.

Michael Mansfield, who represented Dodi's father Mohamed Al Fayed at the inquest in 2008 into Diana and Fayed's deaths, said Diana's killers had no intention of ending her life in a Paris underpass in August 1997, the Daily Express reported Friday.

He claimed that an attempt to scuttle her relationship with Dodi backfired.

An inquest jury had concluded Diana had been killed by the grossly negligent driving of chauffeur Henri Paul and pursuing vehicles.

'I don't believe anyone wanted to see her dead. I think there was a plan to sabotage the relationship and alter her life, to try to stop her activities. But this plan went very badly and ended with her death,' Barcelona-based newspaper El Periodico quoted Mansfield as saying.

Mansfield said the authorities opposed several aspects of Diana's private and public life.

'I believe the relationship between Diana and Dodi displeased the authorities. In spite of all the work Mohamed Al Fayed did for children and hospitals, he was persona non grata in Britain. Diana had given interviews attacking the Royal Family, but what most annoyed the authorities was that Diana became very actively involved in the campaign against land mines,' he said.