Highly personal voicemails left by Princess Diana may have been hacked in the months before her death, sources close to her former lover have claimed.
Hasnat Khan, the eminent heart and lung surgeon who conducted a two-year relationship with the princess, believes messages left on his phone were illegally intercepted as far back as 1996.
Last summer the 53-year-old was informed by Scotland Yard that it was possible his voicemails had been improperly accessed in 2007 in the months before the high-profile inquest into Diana's death.
But sources close to the Pakistani doctor said he now fears the hacking may have begun a decade earlier, at the height of his secret relationship with the princess.
The source said: "It is only when Dr Khan started to think back to the time when he was with Diana that it began to occur to him that someone may have been trying to listen in to his messages.
"Their friendship was very private and very discreet but he now fears journalists were targeting him in a bid to find out what was going on.
"He is very angry about it and it just goes to show how long ago this activity stretches back."
Dr Khan, whom the princess referred to as Mr Wonderful, has described hacking as a violation and is pursuing News International for substantial damages.
When he first learned that he might have been a victim, last year, he said: "To know that someone has been listening to your private messages is awful. It's absolutely terrible. It feels as if you have been robbed."
He has vowed to seek the maximum compensation he can and to donate the money to the heart unit he has set up in his native Pakistan.
Dr Khan met Diana in 1995 when she was visiting a friend in the Royal Brompton Hospital.
They began a discreet affair which he ended just months before her death in Paris in August 1997.
He later moved to Malaysia before returning to Pakistan where he has set up a specialist heart clinic for children in his hometown of Jhelum.