Warsaw town hall says the city mayor's husband has returned money obtained from property restitution that was found to be unlawful, a case that had burdened Poland's main centrist opposition party.

Restitution of private property previously seized by the communist authorities has bred many irregularities blamed on Warsaw Mayor Hanna Gronkiewicz-Waltz. She used to be a prominent member of the centrist, pro-European Union party Civic Platform — currently the main, albeit weak, opposition to the right-wing government.

Gronkiewicz-Waltz's husband obtained restitution of a house in Warsaw in a 2003 decision that — a special commission recently said — was unlawful. The commission ordered the return of proceeds the family earned in then selling the house.

Warsaw town hall said Monday the money, some 1.1 million zlotys ($318,000) has been returned.