The accountancy watchdog has launched an investigation into Grant Thornton's audit of Patisserie Holdings and the café chain's former head of finance.

The Financial Reporting Council said the investigation, conducted under the audit enforcement procedure, would examine audits of Birmingham-based Patisserie Holdings for the years ending September 30 2015, 2016 and 2017.

The council has commenced an investigation under the accountancy scheme into the preparation and approval of Patisserie Holdings' financial statements and other financial information by the former finance chief Chris Marsh.

Patisserie Holdings, which is headquartered in Hall Green, owns café and cake groups Patisserie Valerie and Druckers, sandwich shop Philpotts and bakeries Baker & Spice and Flour Power City Bakery.

It has been mired in financial trouble in recent weeks and came close to collapse after finding a black hole in its accounts.

Mr Marsh was arrested on suspicion of fraud following that discovery but was later released and has since left the group.

Last month, Luke Johnson, its chairman and majority shareholder, injected £20 million of his own wealth to keep the company afloat.

And last week, Paul May stepped down as chief executive of Patisserie Holdings after 12 years in the post, to be replaced by Steve Francis who has significant experience in turnaround work.