The farm ministry was first tipped off about Mikasa Foods' distribution of inedible tainted rice in January 2007 but was unable to uncover any wrongdoing, Agriculture, Forestry and Fisheries Minister Seiichi Ota told the Diet on Thursday.

"I would like to deeply apologize to the consumers and the public for causing concern and trouble over the issue of the illegal distribution of tainted rice," Ota said.

Special hearings of the Agriculture, Forestry and Fisheries Committee were held in both the Lower and Upper houses. Ota admitted during the hearings that the farm ministry received information on the tainted rice in January 2007 but was unable to uncover any illegalities at that point.