The 51-year-old detective constable was arrested while at work and bailed as part of continuing investigations by Scotland Yard. He has also been suspended.
A second man, aged 35, has been arrested by appointment as part of the Operation Weeting investigation.
The names of both individuals have not been released.
The Deputy Assistant Commissioner of police Sue Akers said the police officer's arrest was "hugely disappointing".
She said, "I made it very clear when I took on this investigation the need for operational and information security. It is hugely disappointing that this may not have been adhered to".
She added, "The MPS (Metropolitan Police Service) takes the unauthorised disclosure of information extremely seriously and has acted swiftly in making these arrests".
The name of the second man, according to the Daily Telegraph, is Dan Evans, a former News of the World feature writer, who has been arrested for allegedly intercepting voicemails.
A News International spokeswoman said: "We are fully co-operating with the police investigation and we are unable to comment further on matters due to ongoing police investigations".
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