A top management consultancy firm which said it was "deeply regrettable" that its employees had leaked confidential plans being discussed on building an 800-bed super hospital to replace Epsom and St Helier has refused to reveal whether they faced any consequences.

Consultants from Deloitte shocked health campaigners, politicians and patients last month when it emerged they had held a conference call on the proposals on a commuter train, after a meeting with hospital trust chief executive Daniel Elkeles.

Last month: Secret plans to close Epsom and St Helier and build new "super hospital" overheard on train

Less than three weeks before, Mr Elkeles told this newspaper that accident and emergency, maternity and children’s services would all be safe on both sites for the next five years and "people don’t have to worry about putting out the placards".

The Deloitte consultants are on the payroll of the trust as part of its "full estates review", through which it is considering options for the sustainability of both hospitals post-2020.

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Campaigners protesting outside Epsom Hospital last month after the Deloitte leak 

The review is being funded by the trust and Sutton and Surrey Downs Clinical Commissioning Groups.

Last week: Epsom and St Helier chairman apologises for "super hospital" leak

As news of the leak broke last month, Mark Smith, public relations and public affairs manager for Deloitte, said: "We have clear and strict policies, along with mandatory annual training for all staff, emphasising the importance of client confidentiality.

"This is a deeply regrettable incident and we are actively investigating the matter."

But asked on Thursday what had come of the investigation and whether any action had been taken against the employees involved, Mr Smith said that because it was an "internal matter", the company would not be commenting.

Deloitte is the largest provider of professional services in the world and provides consulting, tax, audit, financial advisory services and more.

It is known as one of the 'Big Four' professional services firms alongside PwC, EY and KPMG.