TOKYO — Two years ago, Toshio Tamogami, a deeply conservative former military commander turned politician, drew more than half a million votes as a candidate for governor of Tokyo, fueling concerns about the growing appeal of far-right ideology in Japan.

On Thursday, Mr. Tamogami was in jail, arrested on suspicion that he violated election laws during his campaign for governor.

Mr. Tamogami, 67, is accused of paying 2.8 million yen, or about $25,000, in salaries to five members of his campaign staff who, under the law, were supposed to be working as volunteers.

The finance director for his 2014 campaign was also arrested on Thursday, the Japanese authorities said.