The past denial of child-care allowance to unwed mothers after men stepped forward as the fathers of their children was illegal, the Supreme Court ruled Thursday, because divorced mothers receiving alimony were already entitled to the payment.

The top court's No. 1 petty bench made the judgment in two suits filed by single mothers in Nara and Hiroshima prefectures who received contradictory rulings from lower courts on the Child Support Allowance Law.

"Recognition of paternity does not necessarily guarantee that the fathers will act as breadwinners for the households," Judge Kazutomo Ijima said. "And in reality, child support is not always paid by them."