The government failed to pay about 30 billion yen in pension benefits to the wives of wage earners since 1991 while overpaying some 2.4 billion yen to others since 1999, the Social Insurance Agency said Friday.

Some 36,000 wives did not receive a special dependent's benefit paid to married men under the corporate employee pension program. The benefit was supposed to be transferred to the wives' pensions when they became eligible for the national pension at age 65.

The agency said the maximum missed payment stood at some 2.8 million yen per person. It blamed the mistake on human error.

It said it will make up for the missed payments, starting with pension payments slated for September.

Meanwhile, 7,200 people were overpaid by as much as 1.2 million yen, the agency said. The people will be asked to make repayments in a lump sum or in installments.

It said the overpayments were due to a computer programming error.

Health, Labor and Welfare Minister Chikara Sakaguchi apologized for the blunders.

"We will thoroughly investigate and uncover the causes for the errors," he said, "as the problem threatens to undermine confidence in the pension system."