Phone hacking by journalists in the U.K., which has centered on News Corp., may have targeted PR firm Citigate Dewe Rogerson, according to reports.

The firm, a top London M&A and financial PR advisor, has acknowledged that it was alerted by a mobile provider in 2011 that police were investigating unauthorized hacking into three Citigate mobile phones.

The hacking was centered on attempts in 2005 and '06 and the firm told the U.K.'s City A.M. that there has not been recent follow-up and it does not believe the inquiry is ongoing.

The Daily Mail noted the revelation by Citigate is the first time the hacking scandal has involved market-sensitive information rather than celebrity or crime reporting.

A senior Citigate exec told the paper that he was told by mobile provider O2 that his phone had been hacked "over an extended period." The exec added: "It is something which could have damaged my professional reputation if word of a deal got out."

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