Supporters of Indonesia's Prabowo Subianto are celebrating his likely ascent to the presidency, but for Paian Siahaan it is a painful reminder of his missing son and the man he blames for his disappearance in 1998.

Paian's 22-year-old son Ucok was one of the pro-democracy activists who disappeared during the chaotic riots of 1998 that precipitated the end of authoritarian leader Suharto's decades-long rule, at a time when Prabowo was an influential military commander.

A report by Indonesia's rights commission later indicated that Prabowo and several other soldiers were involved in kidnapping the activists, but Prabowo never went on trial, and has always denied any wrongdoing.