Police said one man was arrested in a dawn raid on his home in north London as part of Operation Tuleta, an investigation into computer hacking linked to Britain's phone-hacking scandal.
"Officers from Operation Tuleta arrested a man at his home in north London at about 6.30am (530 GMT) this morning," a Scotland Yard spokesperson said, adding that no further details were immediately available.
British media named the journalist as Sun reporter Rhrodri Phillips.
News International, the British newspaper arm of Murdoch's US-based News Corporation media empire, confirmed that one of its employees had been detained.
"A journalist from the Sun was arrested this morning," a spokesperson said.
The arrest is the seventh as part of Operation Tuleta.
Tuleta is one of three linked inquiries sparked by the phone-hacking scandal at Murdoch's now defunct News of the World weekly tabloid.
The operation is being run alongside Operation Weeting, an investigation into phone hacking at British newspapers, and Operation Elveden, into inappropriate payments by journalists to police and public officials.
More than 60 people have been arrested in the three investigations, including Rebekah Brooks, a former top aide to Murdoch and friend of British Prime Minister David Cameron, and Cameron's former media chief Andy Coulson.
Australian-born tycoon Murdoch closed the 168-year-old News of the World in July 2011 after revelations that it had accessed the voicemail of a murdered schoolgirl, as well as dozens of public figures. – AFP