At least 30 university research labs and other facilities across Japan are using cells harvested from dead fetuses -- most of them killed in abortions -- for research into regenerative medicine, the health ministry said Monday.

Scientists regard this as a promising area and hope one day to be able to replace damaged cells and tissue by growing new cells.

However, the research also raises tough ethical questions, given that the increasing use of cells for research has preceded the formulation of any law or guidelines.

To address these issues, the Health, Labor and Welfare Ministry will convene an experts' panel next month. Doctors and experts are still studying the legitimacy of using aborted fetuses for such research.

There has also been a case of a university ethics panel approving the transplant of cells to a patient's heart.

A health ministry study group conducted a survey last spring on about 1,500 university laboratories and medical facilities conducting research into regenerative medicine.

The group found out that about 30 institutions had used cells taken from dead fetuses for research purposes, including five which had imported the cells.

However, the study group suspects the actual number of such institutions is probably higher.

Research is focused on finding a renewable source of replacement cells and tissues to repair damage to cranial nerves, the spinal cord, heart muscles and other parts of the body.

In Japan, cells harvested from aborted fetuses are also used for research into new vaccines, virus development and aging.