During oral submissions this morning, counsel Gurdial Singh Nijar said the inquiry into Koh’s disappearance should resume despite a police order on January 16 to halt the proceedings.
The inquiry was suspended after police said they had charged part-time Uber driver Lam Chang Nam with kidnapping the pastor.
Suhakam officer Joshua Ericson said today there were four more witnesses, including three police officers, to testify in Koh's case.
He said the police observers were summoned to give their oral submissions, but had said they would not attend after receiving advice from the Attorney-General's Chambers (AGC).
Koh family lawyers said police had an obligation to attend the inquiry and explain the evidence they had on Lam, the suspected kidnapper.
"Their absence makes it look as though the state or police are trying to stifle this inquiry," Gurdial told the panel.
"They (police) have disappeared (from the hearing). It's not enforced disappearance, but voluntary disappearance.
"There was an attempt to stonewall the inquiry."
Ericson said the officers would likely challenge the summons issued by the commission.
"If we summon them and they challenge and put a stop to it, then it will delay the inquiry.
“(But) if we are to continue, should the panel come to a conclusion based on what the inquiry has gathered so far (on Koh's case)?"
Gurdial said the panel had the power to summon any person in the country to give their testimony, and urged the panel to lodge a police report against the police observers if they did not attend.
He said the officers would be in violation of Section 174 of the Penal Code, which carries a punishment of a jail term and fine.
Suhakam commissioner Mah Weng Kwai said earlier police had stated, through a letter dated February 6, that they would not file their written submissions on the suspension of the inquiry, on the advice of the AGC.
Police had used Section 12(3) of the Suhakam Act 1999, which states that if the subject of an inquiry is heard in the courts, the commission shall immediately cease the inquiry.
Koh’s family, however, want the inquiry to proceed, claiming that the subject matter before the court is different from what is before the inquiry.
While the court is to hear a case of alleged kidnapping, the inquiry is to determine whether Koh’s disappearance was due to state-enforced actions.
Koh was abducted in Petaling Jaya on February 13 last year by some 15 men in three black SUVs.
His family members are wife Susanna Liew, son Jonathan, 33, and daughters Esther, 32, and Elizabeth, 22.
Mah chairs the Suhakam panel, which includes two other commissioners – Aishah Bidin and Dr Nik Salida Suhaila Nik Saleha.