Police have found evidence that Sara Payne, the mother of Sarah Payne, the eight year old who was was abducted and murdered in July 2000, could have been targeted by the News of the World's investigator Glenn Mulcaire.

The revelation that Payne's phone could have been hacked is particularly shocking in light of her close relationship with the newspaper, which under Rebekah Brook's editorship campaigned for a change in the law to allow the identification of paedophiles. Brooks said that the battle for "Sarah's Law" was one of her proudest achievements.

When she heard that the newspaper was going to be closed, Payne gave a heartfelt statement in which she said "it feels like a friend had just died". She also said:

The NOTW team supported me through some of the darkest, most difficult times of my life and became my trusted friends. One example of their support was to give me a phone to help me stay in touch with my family, friends and support network, which turned out to be an absolute lifeline. A lifeline policy that we now adopt as victims' advocates. Since Sarah was murdered, my marriage broke down, my brother passed away, then my mother and then my father. I just don't know what I would have done without being able to reach out to my friends and family 'whenever I needed them' during these very dark times and it helped me stay in touch with the NOTW team regarding their support for my campaign to bring about Sarah's Law which went national this year.

It is thought that the evidence that police have found in Mulcaire's notes relate to this phone -- which, according to the Guardian, was given to Payne as a gift by Brooks. In the same statement, Payne said it would be a "devastating intolerable betrayal" if her phone had been hacked. She even wrote a column in the final issue of the newspaper.

This latest development will reignite speculation about how much Brooks knew about phone-hacking, given her close involvement with the Payne case and the campaign for "Sarah's Law" as editor of News of the World. Brooks denies any knowledge of phone-hacking. She told MPs last week that "we only know what we have read", and said she was horrified to read in the Guardian that the murdered schoolgirl Milly Dowler's phone had been hacked.

If the allegation does turn out to be true, the key question will simply be "why?", given that Payne had a close working and personal relationship with senior executives at the newspaper.

UPDATE 17.30

Rebekah Brooks has given a statement confirming that Payne was given a phone by the newspaper: