An Osaka couple jailed for life over a 1995 arson and murder have been granted a retrial following a ruling by the Osaka High Court on Friday.

Turning down prosecutors' objections, the court upheld a 2012 district court decision to grant the retrial and will suspend their sentences from the start of next week.

Keiko Aoki, 51, and Tatsuhiro Boku, 49, were jailed in 1995 after being found guilty of setting their house on fire in a bid to kill Aoki's 11-year-old daughter Megumi and collect life insurance money.