The Health and Welfare Ministry in 1988 ignored a report compiled by a ministry research team warning that transplant patients who received imported dura mater could contract Creutzfeldt-Jakob Disease, a rare and fatal disease, an internal ministry investigation revealed Friday.

In February 1988, the head of the research unit submitted the report at a meeting attended by 20 experts and three ministry officials, ministry sources said.

The report, based on three years of research, warns of a link between using imported dura mater -- the fibrous membrane surrounding the brain and spinal cord -- and CJD, citing a 1987 U.S. report detailing the first-ever case of a transplant patient contracting CJD, the sources said.

In March 1997, nine years after seeing the report, the ministry recalled the dura mater products, in effect banning the use of dura mater.

The ministry first approved imports of dura mater from Germany in 1973. It was processed by a German pharmaceutical company for use in transplants after being extracted from dead bodies.

Ministry officials defended the decision, saying no concrete measures could be taken based on a report alone.

Speaking to reporters Friday after a Cabinet meeting, Health and Welfare Minister Yuji Tsushima said the ministry will soon release its findings. "We will show the public all the materials and documents we have regarding the matter," he said.

Tsushima said that although dura mater was considered one of the factors possibly connected to CJD, "it was not yet clear and conclusive back then."

He said groundbreaking treatments have inherent risks, adding that the ministry's responsibility should be judged after the case is presented in a court of law.

The report is likely to be welcomed by CJD patients who have filed compensation lawsuits against the ministry for failing to inform them of the risk of contracting the disease.