Thailand's supreme court Tuesday upheld a 2011 not-guilty verdict in the enforced disappearance case of Somchai Neelapaijit, a prominent Muslim lawyer and human rights activist. The anticipated verdict is expected to set a precedent for similar cases in the future.

In Tuesday’s ruling, judges said that Somchai's family could not become co-plaintiff in the case because there was no evidence to show if he was dead or seriously injured, Channel News Asia reported. Somchai was allegedly abducted on March 12, 2004, while defending suspected militants believed to have been tortured under police custody. Five police officers were reportedly seen putting Somchai into a car in Bangkok after which the lawyer was never seen.

The alleged abduction happened during Thaksin Shinawatra's administration, which saw a rise in tensions between the country’s army and Islamist militants. Thaksin had said in 2004 that an investigation into the case suggested that Somchai may have been killed by officials. Five officers stood trail in 2005 on charges of coercion and robbery. While one of the officers was convicted and later went missing in a landslide, four others walked free. In 2011, an appeals court acquitted all five police officers of the charges.

Somchai’s daughter Pratubjit Neelapaijit reportedly called Tuesday's ruling a “failure of the judicial process.” His wife Angkhana Neelapaijit, now a human rights commissioner, had said earlier this month that the apex court’s verdict will have a bearing on future enforced disappearance cases.

“My long battle through Thailand’s justice system has shown me Thailand’s laws are currently inadequate to deal with cases of enforced disappearance and that significant reforms are needed before the rights of victims are fully recognized,” Angkhana had said, in a statement.