The apology comes two days after the government decided not to appeal against a court ruling that it must pay compensation to more than 100 former patients.

But in a separate statement, the government disagreed with the court verdict saying it would severely restrict the activities of legislators.

"The government seriously reflects and offers its frank apology over the pain and suffering of the patients and former patients," he said in a statement.

He also announced a series of measures including:

• enacting a law to compensate all victims
• providing special pensions for all leprosy patients
• promoting public awareness of the disease

Earlier this month, the Kumamoto district court in southern Japan ordered the government to pay 127 former leprosy patients a total of 1.82bn yen ($14.8m) for failing to change a policy of isolating them after 1960, when drug therapy allowed out-patient treatment.

Inhuman treatment

Under the draconian 1953 Leprosy Prevention Law, which was repealed only in 1996, patients - including young children - were forced to leave their homes and enter the special medical centres.

In an emotional meeting, they described their treatment in the centres and how they were discriminated by friends and even relatives.

"For 60 years, I was not treated as a human," a former patient and plaintiff in the Kumamoto case, Mamoru Kunimoto, said.

"But the fact that the government will not appeal has given me back my humanity."

Mr Koizumi said the decision not to appeal was made on humanitarian grounds but maintained that he did not agree with the court ruling.

Some members of the government are worried about the impact of the ruling which, they fear, could set a precedence for other compensation claims.