The New Zealand pilot was taken hostage on February 7 last year in Paro, Papua, while providing vital air links and supplies to remote communities.
In the recent videos he is seen surrounded by armed men and delivers a statement, saying his life is at risk because of air strikes conducted by the Indonesian military.
He asks Indonesia to cease airstrikes and for foreign governments to pressure Indonesia to not conduct any aerial bombardments.
RNZ has sought comment from the Ministry of Foreign Affairs and Trade.
Earlier this year, Foreign Minister Winston Peters strongly urged those holding Mehrtens to release him immediately without harm.
Peters said his continued detention serves no one's interests.
In the last year, a wide range of New Zealand government agencies has been working extensively with Indonesian authorities and others towards securing Mehrtens' release.
The response, led by the Ministry of Foreign Affairs and Trade, has also been supporting his family.
