TOKYO: Japan's former premier Junichiro Koizumi, known for crooning Elvis Presley songs while in office, is lending his voice to a superhero movie, reports said Tuesday.

Lion-maned Koizumi, 67, has provided the voiceover for the extraterrestrial hero who fights not political opponents in the Diet legislature but monsters and aliens from outer space, according to the movie's producers.

Koizumi, now retired from politics, used his offbeat charisma to rule Japan for more than five years until 2006, in contrast to his three conservative successors who each quit the post of prime minister within a year.

While in office, Koizumi displayed his media savvy by singing Elvis hits during a visit to Graceland, Tennessee, with then US president George W. Bush.

His next performance will be in "MegaMonsterBattle -- Ultra Galaxy," which is due to be screened in Japan on December 12. His character fires a flash of light to attack evil enemies and shouts: "Pay for your transgression!"

"No one else can play this significant role except for former premier Koizumi, who once led the country," said Junko Kitazawa of Tsuburaya Production, which made the latest movie version to the TV series.

Koizumi first planned to decline the request to appear in the movie but changed his mind after his son, Shinjiro, who took over his seat in parliament in the recent elections, encouraged him to accept it, reports said.

Koizumi's eldest son, Kotaro, is a professional actor.

The Ultraman television series first appeared on TV in 1966. Ultraman, a silver-suited masked hero, comes from outer planet to save the Earth from gigantic monsters.

"The Ultraman series can be enjoyed by an entire family over three generations," Koizumi told Nippon Television.