Suspected murderer on the run for 45 years is arrested in Japan

Masaaki Osaka allegedly used a petrol bomb to set a police officer on fire

Masaaki Osaka (C), once a high-ranking member of the Japan Revolutionary Communist League, arrives at Tokyo's Haneda airport (AFP/Getty Images)

A suspected murderer who went on the run for 45 years has been arrested in Japan.

Masaaki Osaka, a left-wing revolutionary, has been charged for murdering a police officer during a street protest in Tokyo.

He evaded investigators for almost five decades after he allegedly set the officer on fire using a petrol bomb in 1971.

Osaka was a member of the Revolutionary Communist League National Committee, often referred to as Chukaku-ha, the Japan Times reported.

He was initially arrested for allegedly obstructing police officers who raided an apartment used as a hideout of the Chukaku-ha while searching for a fellow activist.

Police say Osaka was able to remain on the run for so long because sympathetic party associates assisted him.

His identity was confirmed through DNA tests and he has apparently remained silent since being caught.

He has now been taken to Tokyo for further questioning.

There was a 15-year statute of limitations on crimes in the country but this was abolished in 2010.