The Department of Special Investigation (DSI) has pledged to look into a decision by prosecutors to drop serious charges against four park officials suspected of being involved in the 2014 killing of Karen activist Porlajee "Billy" Rakchongcharoen.
DSI director-general Pol Lt Col Korrawat Panprapakorn on Thursday met Pinnapa Prueksapan, Porlajee's wife, at her home in Phetchaburi province.
He told Ms Pinnapa he would take a thorough look at the prosecution's decision.
Pol Lt Col Korrawat asked Ms Pinnapa about her safety because she was a key witness in the case of her husband's murder. He vowed the DSI will make sure justice is served.
In January, state prosecutors dropped murder charges against Chaiwat Limlikit-aksorn, former head of Kaeng Krachan National Park, and three others accused of being involved in the death of Porlajee.
The move dismayed activists who believe they played a part in his disappearance.
They decided to recommend indicting the four only for failing to hand over the activist to police after he was arrested in April 2014 for allegedly collecting wild honey at the national park in Kaeng Krachan.
