Court investigations into the “Adhoc 5” who were jailed more than a year ago over opposition leader Kem Sokha’s alleged extramarital affair finally closed this week, with a jurist saying their continued detention without trial would only “erode the little faith the public has” has in the judiciary’s neutrality.

Adhoc staffers Lim Mony, Ny Sokha, Yi Soksan and Nay Vanda, and elections official Ny Chakya have been in prison since April 2016 over CNRP President Kem Sokha’s alleged affair. Four were charged with “bribing” his alleged mistress to deny the affair, while Chakrya charged as an accomplice.

Lor Chunthy, a lawyer for the Adhoc officials, said he was informed the investigation into their case closed on Tuesday and that a closing order was due in two weeks to either drop the charges or initiate a trial. “If the case is sent to a trial, [the court] needs up to four months to set a date,” he said.

Kingsley Abbot, senior legal adviser with the International Commission of Jurists, said the refusals to release the five on bail or move the case forward over the past 15 months would inevitably create perceptions of politicisation given pretrial detention was needed only in special circumstances.

“The lack of public information to dispel these concerns will further erode the little faith the public has in the criminal justice system and reinforce the perception that the prosecution and judiciary lack independence and impartiality in carrying out their work,” Abbot wrote in an email yesterday.

The pretrial detention of the “Adhoc 5” began in April 2016 and was first extended by six months in October, and then again this April, with Investigating Judge Theam Chanpiseth saying he needed time to question more witnesses.

When Judge Chanpiseth had suggested closing the investigation in January, Court Prosecutor Kuch Kimlong rejected the idea saying that investigations were still incomplete.

None of the five have been questioned by judges or prosecutor since last year even as they made filings to the Appeal Court and Supreme Courts in efforts to secure bail. Only one “witness”, Adhoc’s deputy for human rights monitoring, Pen Sinav, has been called to court – in February.

The UN’s Working Group on Arbitrary Detention had two months before called their detention “arbitrary” amid reports of the stalled investigations and said that Cambodia was accordingly violating its obligations under international laws.

Adhoc spokesman Sam Chankea said he thought it was clear the case had been deliberately stalled.

“What I see is that the intention of the court is to extend the detention [to] threaten and make Adhoc staff suffer. That is all,” he said.

Deputy Court Administrator Suos Vithya Randy confirmed the investigation was now closed, but both he and Court Administrator Y Rin declined comment on the pace of the case and the lack of investigations since last year’s arrests.