* Reported hacking took place when Brown was PM and finmin
* Brown family shocked, spokeswoman says
* Wife Sarah tweets 'thank you for your thoughtful messages' (Adds Brown statement)
LONDON, July 11 (Reuters) - Police have said that former British Prime Minister Gordon Brown may have been a victim of phone hacking by an investigator working for British newspapers, his spokeswoman said on Monday.
The Guardian and Independent newspapers reported on their websites earlier on Monday that journalists from Rupert Murdoch's newspapers repeatedly tried to hack into Brown's voicemails when he was finance minister and prime minister.
The Guardian said News International reporters had repeatedly targeted Brown, trying to access his voicemail and obtaining information from his bank account, his legal file and his family's medical records.
Brown's spokeswoman said his family was shocked, but did not give details.
"Gordon Brown has now been informed of the scale of intrusion into his family's life," she said in a statement.
"The family has been shocked by the level of criminality and the unethical means by which personal details have been obtained.
"The police have confirmed Mr Brown is on Glen Mulcaire's list."
Mulcaire was a private investigator at the centre of the News of the World phone hacking scandal.
His wife Sarah Brown said on her twitter page: "So sad to learn all I am about my family's privacy - it is very personal and really hurtful if all true.
"Thanks for your thoughtful messages this eve, really appreciated. Thinking of other families affected who did not ask to be in public eye."
Allegations of illegal reporting practices have centred on the News of the World, Murdoch's mass-selling Sunday paper. The newspaper reports alleged that there had been similar malpractice at sister papers in the News International stable.
Murdoch closed down the News of the World after it published Sunday's edition because of the spreading scandal, but his three other British papers, the Sun, the Times and the Sunday Times, are still operating.
News International, part of Murdoch's News Corp group , said in a statement that it noted the allegations concerning Brown. "So that we can investigate matters further we ask that all information concerning these allegations is provided to us," it said.
The Guardian said it had uncovered evidence that Brown had been targeted over a period of more than 10 years, both as finance minister and as prime minister.
It also reported that a building society had unearthed evidence suggesting that a "blagger" acting for the Sunday Times posed as Brown on six occasions and gained details from his account.
It also said Brown's London lawyers had been tricked into handing over details from his file by a conman who, it said, worked for the Sunday Times.
In addition, and perhaps most damaging, a Guardian investigation found that details from Brown's infant son's medical records may have been obtained by the mass-market Sun.