A top consultancy firm looks set to lose thousands of pounds after its staff held a conference call about radical plans for Epsom and St Helier hospitals on a train.

Management consultants for Deloitte, one of the 'Big Four' professional services firms, were overheard last month discussing the option of closing both hospitals and replacing them with an 800-bed super site in Sutton.

They were on their way back from a meeting of the trust's programme board which is looking into how to make its buildings sustainable post-2020.

Deloitte refused to reveal to this newspaper last week whether any action had been taken against the employees involved, having previously called the incident "deeply regrettable".

From yesterday: 'Traingate' - Hospital chief exec says "I don't think we misled anyone" over leak of super-site plans

But Daniel Elkeles, the hospital trust's chief executive, said the company is still working for it on its "estates review" following the incident - which he has dubbed Traingate - although its contract is being renegotiated downwards as a result of the hugely embarrassing incident.

He said: "They were clearly in breach of the contract they had with us and as a result of that we have almost finished renegotiating the contract with them because as you would expect they need to compensate us for breaching their client trust.

"We have been working with them on how they are going to do that.

"The contract was for more than £50,000.

"We hope we will have concluded the renegotiation in time for the June board meeting.

"In the middle of a negotiation, I can't tell you [how much will be compensated] now."

Earlier this month: Top consultancy firm refuses to reveal whether employees faced any action over shocking 'super-hospital' leak

A trust spokeswoman said it could not say how much the Deloitte contract had been worth in total "since the contract is currently being renegotiated with the consultants involved".

She said the information should be released at its next trust board meeting on June 26.

Mr Elkeles - who has not heard the transcript of what the consultants were overheard to be saying - said it was "quite right" that people were shocked by the media reports that followed.

"What was reported was very different from the news that Epsom and St Helier wanted people to hear about," he said.

"Did we feel let down and upset? Of course we did. But it happened and you have to carry on."