Prosecutors and police in Hyogo Prefecture, western Japan, conducted searches at several locations on Friday over a possible violation of the public offices election law.

Hyogo Governor Saito Motohiko has been accused of paying a PR company for his online campaign during last year's gubernatorial election, in which he was reelected.

After the election, the PR firm's representative wrote on a website that the firm handled the strategic planning of social media operations for the campaign.

In December, a lawyer and a university professor filed a complaint with the Kobe District Public Prosecutors Office and the Hyogo prefectural police, alleging that Saito and the PR company representative violated the election law.

They say the payment Saito made to the firm may have constituted a reward for its online election campaigning activity, which could be considered bribery.

Investigators are expected to study the confiscated documents carefully before deciding whether to file criminal charges.

Saito told reporters on Friday that he learned of the investigation via media reports. Maintaining his position that he did not violate the election law, he said he will fully cooperate with the investigators.

The PR company representative has not responded to any of NHK's requests for comment.