The trust reported a deficit of �8.1m in March

In March the trust, which runs the Royal Cornwall Hospital in Truro, reported a deficit of �8.1m and announced that 300 jobs would go.

The trust now says the overspend is greater but will not release a figure and declined to comment on speculation it could be as high as �18m.

Auditors are looking at the accounts and will report in two weeks.

Price Waterhouse Cooper is working with the trust to produce a plan which will help it pay off the debt and help to balance the books in the future.

St Ives Lib Dem MP Andrew George said: "I was sceptical that the deficit was as little as �8.1m at the time the announcement was made in March.

"Sources I have heard from suggest we're talking about something which is quite substantially more."