Osaka residents opposed to the city burning Tohoku quake and tsunami debris filed an audit request with the prefecture and the city Friday questioning the financial logic behind the move and saying there is no guarantee that expected central government funding for accepting the rubble will come through.

Osaka is to begin burning 6,000 tons of debris from Iwate Prefecture on Feb. 1. The resulting ash will be used as fill for a man-made island in Osaka Bay.

Osaka Prefecture signed a contract with Iwate Prefecture in November to accept the waste and then signed a separate contract with the city of Osaka to burn 6,100 tons of it by the end of March at a cost of more than ¥94 million.

Another 30,000 tons are scheduled to be disposed of in fiscal 2013 at an initially projected cost of about ¥387 million.

Under the arrangement, the city will first burn the debris and then be reimbursed almost 100 percent by the central government. But opponents worry that the city may not get the full amount as the ultimate decision on reimbursement lies with the Environment Ministry.

"We don't know how much money will actually be reimbursed because there is no standard regarding the regional disposal of the debris. So it's unclear if we might be stuck with a large portion of the bill," said Hannan University professor Masaki Shimoji, one of leaders of the push for an audit.

Many audit-seekers say the real reason Osaka agreed to take the debris has to do with the ambitions of Mayor Toru Hashimoto.

"By accepting the debris, Hashimoto hopes to gain broader political support in Tokyo and Tohoku for his Nippon Ishin no kai (Japan Restoration Party)," said activist Katsunori Matsushita.