The former legal advisor to Rupert Murdoch's News International newspaper group was arrested by police investigating alleged phone hacking.
Tom Crone, 60, was held at his home in London on suspicion of conspiring to intercept communications and was taken for questioning at a police station before being bailed to return on a date in mid-October.
He is the 25th person to be arrested under Operation Weeting, the Metropolitan Police's investigation into allegations of phone hacking, mainly at the now-defunct News of the World.
The probe is being run alongside two separate investigations -- Operation Elveden, which is looking at alleged corrupt payments to public officials, and Operation Tuleta, which concerns accusations of computer hacking and other privacy breaches including the alleged hacking of stolen mobile phones.
So far 43 people have been arrested under Elveden and 11 under Tuleta.
Rebekah Brooks, the former chief executive of News International and once a close aide to Murdoch, is due to appear at a magistrates court in London on Monday on phone hacking charges, which she denies.
Brooks is accused of one general charge of conspiracy to illegally access voicemails, and two others relating to murdered schoolgirl Milly Dowler and a former union boss.
Seven other people including David Cameron's former spin doctor Andy Coulson appeared at the same court earlier this month to face phone hacking charges.
The group includes six senior members of News of the World staff, who all face the general charge alongside Brooks, as well as specific counts linked to individual cases.
Murdoch shut down the News of the World in July last year after the extent of phone hacking at the tabloid emerged.
The scandal led to a public inquiry into press ethics being set up.