The Martin Sorrell saga continues, with WPP enlisting two law firms to help investigate emails sent to current and former employees following the one-time CEO’s abrupt exit.

The anonymous, encrypted emails are from a WhatsApp group that included former executive assistants to Sorrell, and include chunks of messages between employees both former and current, according to media reports.

One of the emails was reportedly sent by a senior WPP exec to a junior employee, and that the discussion topics included Sorrell’s travel arrangements and company bonus plan.

A WPP spokesperson confirmed to AdWeek that it was investigating, with the help of lawyers, six emails sent from an anonymous source “hiding behind a ProtonMail account based in Switzerland” to one ex-staffer and two current employees.

The spokesperson said WPP was “aware of the original source of the subject matter of the emails, which is a former employee’s mobile device used for work and handed in when the employee left the group”.

This all comes after it was reported that Sorrell left WPP in April due to allegations of staff bullying and claims he’d used company money to visit sex workers in London’s upmarket Mayfair.

B&T has sought further comment from WPP.