The IPCC will examine whether the information allegedly passed on was legitimately made public
The police watchdog is investigating claims that a senior officer in the Met inappropriately disclosed information to a News International executive.
The Independent Police Complaints Commission said it was probing contacts during the original inquiry into phone hacking at the News of the World (NoW).
The IPCC said there was no evidence to suggest any payment was made to the specialist operations branch officer.
Scotland Yard said it had decided not to suspend the member of staff.
IPCC deputy chairwoman Deborah Glass said the allegation raised "important issues of public confidence" in the Met.
"I believe it is right that we independently investigate this to determine if there was any wrongdoing," she said.
Investigators will examine whether the information allegedly passed on was legitimately made public.
The IPCC will also liaise with the ongoing inquiry into media ethics led by Lord Justice Leveson, which resumes on Monday.
The latest development followed a referral on 7 February by the Operation Elveden team, formed to look into alleged police corruption.
The officer in question is not believed to be of a rank senior enough for membership of the Association of Chief Police Officers (Acpo).
The specialist operations branch in which the officer works is responsible for counter-terrorism and protecting the Royal Family and other dignitaries.
The original 2006 phone-hacking inquiry led to the jailing of NoW royal editor Clive Goodman and private investigator Glenn Mulcaire in January 2007.
They had admitted intercepting voicemail messages left on the mobile phones of royal aides.
The police investigation has also led to the arrest of several current and former journalists at the Sun, and at the NoW, which was closed in July in the wake of the scandal.