An American television network last night was due to plumb new depths of prurience in the Princess Diana industry by broadcasting photographs of the dying princess in the wreckage of the Paris car crash which killed her nearly seven years ago.

The CBS network, anxious to outdo its commercial rival NBC, which last month broadcast tapes recorded by the princess about her married life and confrontation with her rival Camilla Parker Bowles in the early 1990s, claimed that the pictures to be broadcast on its 48 Hours Investigates programme were "tasteful".

NBC achieved viewing figures of 17 million with its two-part programme, shown across a country which is still fascinated by the princess and her supposedly fairytale life and ghastly death.

Although photographs taken of Diana in the wreckage of the Mercedes limousine a few minutes after it crashed in the tunnel at the Pont l'Alma on August 31 1997 have been known to exist for years - and were presented to national newspapers in Britain on the day after the accident - none has been openly published, though they may be found on websites.

Diana was still alive and possibly conscious for a while after the crash but suffered heart attacks and extensive internal injuries and was pronounced dead shortly after her arrival at a Paris hospital. The princess, her companion Dodi Fayed, and the car's driver, Henri Paul, all died following the crash, which was survived by bodyguard Trevor Rees-Jones, the only occupant of the limousine wearing a seatbelt.

CBS used the pictures to embellish its documentary, which was largely based on the findings of the 6,000-page report produced by the French police investigation into the crash.

An investigation by Sir John Stevens, head of the Metropolitan police, is being conducted for an inquest hearing later this year.

Clarence House last night refused to comment on the programme but a spokesman for Dodi Fayed's father, Mohamed al Fayed, said use of the pictures would be distressing and distasteful. He added: "All we know is that the stills which appeared in newspaper offices that night in Britain were not published by the editors. We have always believed that was the correct decision."

A spokeswoman for CBS last night insisted the pictures were tasteful: "They are not graphic in any way."