Cambodian police are continuing to “monitor” a monk they claim is linked to a purported terrorist plot, though no arrests have been made in the case.

On Tuesday, Prime Minister Hun Sen announced that authorities had prevented the Khmer National Liberation Front from carrying out an alleged plan to bomb Phnom Penh and Siem Reap.

That night, government mouthpiece Fresh News leaked an audio tape of a woman claiming she had been ordered to pick up the bombs by KNLF founder Sam Serey. She also claimed dissident monk Yen Rotanaksotheavy was to lead the attack, supposedly planned for this Thursday at Wat Phnom.

Despite the lack of arrests two days after the premier first ordered them, National Police spokesman Kith Chantharith said the police will “implement the orders and enforce the law”.

“First, prevent them from doing anything, and second punish them based on the law,” he said. “We won’t kid around with them.”

Khieu Sopheak, spokesman for the Ministry of Interior, said police are “observing” Rotanaksotheavy.

Rotanaksotheavy has been a controversial figure with a history of anti-government activism. He participated in multiple high-profile protests, including in 2014 after the disputed 2013 national election, and during demonstrations against the forced evictions at Boeung Kak and Borei Keila.

The monk denied any connection to Serey, and said that he is aware of police monitoring him 24 hours a day.

The surveillance has made him uncomfortable leaving his living quarters, even to deliver traditional Khmer New Year blessings.

“Please Royal Government, Samdech Hun Sen . . . please does not use religion to play with politicians,” he said.

On Wednesday, the Ministry of Interior released a dossier on Serey, purportedly as evidence to support their case against Serey and the KNLF. It included claims that Serey was raising an army in Norway, and identified filmmaker Bradley Cox as a CIA agent whom Serey met with “secretly”.

Speaking from Turkey, Cox laughed Thursday when told of the accusation, and rejected it. Cox said he has been particularly unpopular with the government after the release of his film Who Killed Chea Vichea?, which suggested the state played a role in the assassination of the popular union leader.

The film was banned in Cambodia and Cox admitted it would be “not smart” for him to return to the Kingdom.

He said the accusations against the KNLF are fabricated in order to “stoke national fervor during an election year”.

“That’s an old trick of theirs,” he added.

Indeed, a similar accusation was levelled against the KNLF leading up to the 2013 elections, with charges against 13 members, including Serey, for attempting to violently overthrow the government. Serey, who has been granted asylum in Denmark, was sentenced in absentia. He has made unconfirmed claims this week that he is in Cambodia, having illegally crossed the border from Thailand.

Cox said he had a long relationship with Serey, who was his translator when he was based on Bangkok.

Through Serey, Cox met other KNLF members, whom he described as “harmless”.

“It was a group of guys who wanted to put out leaflets,” he said.

While over 20 KNLF members have been arrested for having allegedly concocted various violent plots throughout the years, there has been no evidence presented of their possessing weapons.

Despite this, Cox did cut off relations with Serey two years ago for being “reckless” and “hugely irresponsible” by knowingly sending his supporters into situations where they would be arrested.

Ear Sophal, associate professor of diplomacy and world affairs at Occidental College, said in an email that the allegation against Cox is “insane” and “smacks of S-21 type fantasy”, referencing the Khmer Rouge prison in Phnom Penh where inmates were often tortured until they confessed to working for the CIA.

“This is part of a narrative in the build-up to the July Elections: vote for us or there will be violence and instability; a color revolution, a KNLF terror plot, fill-in the blank,” he said.

On Wednesday, the US Embassy issued a security warning based on the threats, telling citizens to be careful when travelling in the area of the alleged plot, which is close to the embassy. “U.S. government personnel have been advised to exercise caution around Wat Phnom and be aware of their surrounding in general,” the statement says.

It also advises to “leave the area immediately” if an “unattended object” is observed.