Development comes as concerns about human rights situation leave Cambodia’s EU trade privileges in the balance.

A judge in Cambodia has closed the investigation into treason charges against opposition leader Kem Sokha, which means he could now be brought to trial or the charges could be dropped, his daughter said on Friday.

With the European Union threatening to suspend Cambodia’s trade benefits, the government under Prime Minister Hun Sen is under growing pressure on human rights.

Kem Sokha was freed from house arrest last weekend and Hun Sen ordered the release of more than 70 opposition activists on Thursday. The activists had been detained as exiled opposition leader Sam Rainsy said he planned to return home.

A letter from investigating judge Ky Rithy to Kem Sokha’s lawyer on Friday said: “We decide to close the investigation from this time onward.”

Kem Sokha’s daughter Monovithya Kem said on Twitter: “Next step is either the prosecutor drops the charges or takes the case to trial. We demand that all charges be dropped.”

Breaking: Investigating judge closes the investigation on #KemSokha’s case. Next step is either the prosecutor drops the charges or takes the case to trial. We demand that all charges be dropped. #Cambodia pic.twitter.com/zvhxOeGS8p — Monovithya Kem (@KemMnv) November 15, 2019

A spokesman for the court said he was not aware of the decision to close the investigation so could not comment.

Kem Sokha was arrested in 2017 and his Cambodia National Rescue Party (CNRP) was banned in the run-up to an election last year that was condemned by Western countries as a farce.

Kem Sokha has dismissed the charges against him as nonsense.

On Tuesday, the EU gave the government a one-month deadline to respond to a preliminary report on the suspension of trade preferences over the crackdown on the opposition, non-governmental groups and the media.

Prime Minister Hun Sen, a former Khmer Rouge commander, has ruled the country of 16 million for more than 34 years.

CNRP co-founder Sam Rainsy has been trying to return to Cambodia from exile since last weekend but has found himself barred from flights. He is currently in Jakarta after first landing in Malaysia.