The supermarket said it would co-operate fully with authorities.
Tesco announced on 22 September it had overstated its half year profits by £250m, sending shares tumbling 11% in a day. Year to date, its shares are down 44% and are currently trading at 187p.
Last week, the Financial Reporting Council (FRC) said it is “monitoring the situation closely”, but would wait until the supermarket’s internal investigation is completed.
Tesco’s in-house investigation will be conducted by Deloitte, together with Freshfields, the group’s external legal advisers.
The group has already suspended four executives in connection with the accounting scandal, including UK managing director Chris Bush.
Last week, it admitted its former CFO Laurie McIlwee has not been working the final six months of his contract, encompassing most of the period currently under investigation.
