In a statement released today, the company said that the watchdog had informed them on Friday of the investigation.
“The Financial Conduct Authority informed [Mitie] that the FCA has commenced an investigation in connection with the timeliness of a profit warning announced by the Company on 19 September 2016 and the manner of preparation and content of the Company's financial information, position and results for the period ending 31 March 2016,” the statement read.
The probe is the latest in a series of challenging events for the company which last month saw the company clash with shareholders over the reappointment of Deloitte as auditor.
It was announced that the Big four firm would be investigated over the audit of the company over “material errors” which led to Mitie having to write down £50m of profits.
In 2016 the company lost chief executive Ruby McGregor-Smith when she stepped down in October, and then four months later in February chief financial officer Suzanne Baxter resigned her role.
Mitie said in its statement that they are cooperating, but will not update the market until the investigation is completed.