Martin Sorrell
Martin Sorrell

WPP has hired two law firms to track down the source of leaked emails that were sent to current and ex-staffers following the extraction of CEO Martin Sorrell, according to a report in the Financial Times.

Slaughter and May and Milbank are probing the leaked messages that were sent from a Proton account, which is an encrypted email service in Switzerland used by people seeking to protect their privacy.

The FT, which received some of the anonymous emails, reports the messages sent via WhatsApp discussed Sorrell’s travel arrangements and WPP’s bonus plan.

The ad/PR firm told the FT that it has collated the emails and “passed them to external legal counsel to try to ascertain the sources of the Proton emails and to provide advice for the benefit of WPP and the three recipients.”

WPP had launched an investigation into the personal conduct and use of corporate funds by Sorrell, who has denied any wrongdoing.