Masakuni Murakami, the former Liberal Democratic Party heavyweight at the center of a widening bribery scandal, testified under oath before the Diet on Wednesday but refused to reply to questions that he claimed could incriminate him before his possible indictment by prosecutors.

Appearing before the Upper House Budget Committee as a sworn witness, Murakami refused to elaborate on his ties to the scandal-tainted mutual-aid foundation KSD despite repeated warnings from the committee chairman that his actions could lead to a prison term of up to 12 months.

Murakami, whose resignation from the Upper House was approved by the chamber Monday, maintained throughout the two-hour session that some questions regarding his ties to KSD are best handled by prosecutors.