Ahern ordered the investigation

Justice Mary Laffoy, who was overseeing the investigation into claims of abuse at institutions run by the Roman Catholic Church, said she was stepping down a day after the Irish Government announced plans to speed up the inquiry.

The Government said the commission of inquiry could take up to 11 years to reach its findings and run up costs of 200 million euros ($220m).

Victims' groups have warned that the inquiry might never be revived and have called on the Irish Education Minister Noel Dempsey to resign.

The inquiry was set up to examine nearly 2,000 cases of alleged abuse going back to the 1930s.

'Interference'

Justice Laffoy did not offer any explanation for her resignation, which she said would take effect after her commission published its interim report in November.

The judge had previously accused the government and religious orders of interfering with her work.

I hoped to get a sense of relief and acknowledgement from them, and because this has happened, I just won't get it Alleged victim Patrick McCarthy

Mr Dempsey said he had discussed his proposed review of the commission's work with Justice Laffoy and her decision to quit had "come out of the blue".

The commission, which was set up four years ago, announced an immediate, indefinite halt to its work.

Only 40 out of 1,800 cases of alleged abuse have been completed to date, Mr Dempsey said.

Victims dismayed

Victims' groups blamed Mr Dempsey for the crisis and said the inquiry might be abandoned.

"Going to the Laffoy commission would have given me the chance to face the perpetrators," said alleged victim Patrick McCarthy.

"I hoped to get a sense of relief and acknowledgement from them, and because this has happened, I just won't get it."

Colm O'Gorman, who represents hundreds of alleged victims of abuse by priests, said the commission appeared "dead in the water".

Opposition groups have called for the Irish parliament to return early from its summer break to discuss the matter.