Senior management at Tallaght Hospital have dismissed claims that 30,000 GP referral letters were left unopened.

But the hospital, already facing a storm of controversy after 57,000 X-rays went unchecked, admitted it moved last October to clear a backlog of 3,498 letters which had not been reviewed by a consultant.

The GP who first drew attention to the X-ray scandal, Professor Tom O'Dowd, claimed his written warnings to management about unopened referrals had been ignored.

Embattled Health Minister Mary Harney, who is in the middle of a St Patrick's Day mission to New Zealand, said hospital chiefs gave assurances no letters remained unopened.

"It is completely unacceptable that referral letters from GPs could remain unopened," she added.

"While there are waiting times for outpatient appointments, these should not be prolonged by virtue of GP referral letters not being opened and processed according to clinical requirements."

Tallaght Hospital admitted a backlog of almost 3,500 referrals on top of the X-ray scandal but insisted: "There was never anything like 30,000 unprocessed letters."

The delays were first raised last October.

"All of these are now actively being dealt with," a spokeswoman said.

The spokeswoman added there were currently no unopened GP referral letters in the hospital and staff were focusing on reducing the X-ray backlog. The Health Service Executive, Tallaght Hospital and the Department of Health have said they will offer appropriate care to any patient whose treatment was delayed by unopened letters.