Herbert Smith has been instructed to carry out a review of top journalists' email accounts at Sky News to ensure that there is no evidence of corrupt practices at the company.

The top 10 firm has been instructed by Sky News parent company BSkyB to carry out the review, with City dispute resolution partner Nusrat Zar leading the team for Herbert Smith.

The move is understood to come shortly ahead of the broadcaster's annual general meeting in an attempt to provide assurances to shareholders and staff that there are no illegal practices in the way news is procured at the company.

An all-clear review would allow BSkyB to distance itself from the phone hacking scandal that has engulfed its majority shareholder News Corporation.

According to a story in The Independent today (21 November), the review will include all email traffic from the past five years and centre on a handful of top journalists that are "best-known for breaking stories outside of the regular news cycle".

A Sky News spokesperson said: "There has been no suggestion of any impropriety at Sky News and we remain committed to the highest standards."

News Corporation has a 39% stake in BSkyB and made a failed attempt to take full ownership of the satellite broadcaster earlier this year. Herbert Smith also advised its longstanding client BSkyB on the News Corporation bid, which at one point valued the company at more than £12bn.

The news comes as Lord Justice Leveson last week kicked-off an inquiry into the role of the press and police in the phone-hacking scandal, with the culture, practices and ethics of the media the current topic under consideration.

Berwin Leighton Paisner corporate and commercial disputes partner Graham Shear is set to appear in front of the Leveson Inquiry today.

Shear has been selected to be a core participant in the inquiry both in light of his role as a lawyer acting for some of the phone-hacking victims, and as a victim himself, after it emerged in January this year that his phone may have also been hacked.