A Japanese court has found an election law provision denying prisoners the right to vote in a national poll is constitutional, in the latest ruling in a series of lawsuits filed over the controversial issue.

The Hiroshima District Court on Wednesday rejected a claim by a prison inmate in his 50s who sought the right to vote on the grounds the election law contravenes the Constitution, which guarantees the "inalienable right" to choose public officials.

"We cannot say it is against the Constitution," presiding Judge Masayuki Suenaga said in the ruling, adding there is a "certain degree of reasonableness" in the restrictions set by Article 11 of the Public Offices Election Law, which says imprisoned individuals cannot vote.