Authorities stepped up security for members of a commission charged with recovering the ill-gotten wealth of ousted ruler Ferdinand Marcos after a senior officer was assassinated, officials said Wednesday.

The officials, however, declined comment on who may have been responsible for the slaying Tuesday of Jesus Ronan, operations chief of the Presidential Commission on Good Government, or PCGG.Commissioner Augusto Villarin said police were looking into reports that dismissed employees of the agency or communist rebels acting as "mercenaries" were responsible.