Scotland Yard said that the unnamed 60-year-old man was arrested in south-west London under Operation Weeting, which is specifically investigating the "hacking of telephone voicemail boxes".
The man was arrested on suspicion of conspiring to intercept communications contrary to Section 1 of the Criminal Law Act 1977, the police said.
The arrest comes as Justice Leveson is reported to preparing his report on the culture, ethics and practices of the British press.
The Leveson Inquiry was set up in the wake of the phone-hacking controversy, and heard evidence from leading lights in the press, politics and police live on television.