Prosecutors have searched several locations linked to former Tokyo Gov. Naoki Inose as part of an election investigation into ¥50 million he received from a major hospital chain, sources said.

Inose, 67, has repeatedly maintained the money provided by Tokushukai in November 2012 was a personal loan, but Torao Tokuda, founder of the hospital chain, was quoted as telling the prosecutors it was to be used for Inose's election campaign.

If the ¥50 million was channeled to his election bid, Inose would be obligated to list it in his funds report for the campaign. The funds were not reported. The locations searched included Inose's personal office, the sources said Saturday.

The move came after a citizens' group filed a criminal complaint claiming Inose violated the Public Office Election Law by failing to list the Tokushukai money.