The owner of a Siem Reap printing shop remained in police custody last night along with one of his employees in the wake of a Monday night raid that saw 500 T-shirts with anti-election slogans seized by local authorities.

The shirts were commissioned by the US-based Khmer People Power Movement, an organisation previously likened to a terrorist group by Prime Minister Hun Sen, who in May publicly accused them of training armed anti-government forces in Thailand.

Part of an order of 1,000 placed with the Cambodia T-shirt Printing House in Siem Reap, the T-shirts bore slogans calling on citizens to boycott the election because they are “not free and fair”.

A worker at the print shop, who asked to remain anonymous, said the shop’s owner and a designer had been detained on Monday night and remained in police custody.

“They took them to Siem Reap police station after they raided our shop. Then this morning, the police brought them back to find more evidence. After that, they took them back to the station,” he said yesterday.

Two laptops and 500 T-shirts were confiscated, he added, while the shop remained open for business.

KPPM head Sourn Serey Ratha confirmed yesterday via email that the T-shirts were commissioned by his organisation to donate to Cambodians before the election, emphasising that the group’s actions were allowed under freedom of expression laws.

“KPPM [does] not believe in [the] election and learned that the election in Cambodia is only a political tool of CPP for legalising its power . . . this is the reason why we promote and provide this awareness to people and encourage Khmer people [to] use power to [rise up] instead” he said.

The slogan printed on the shirts said: “Cambodians unite to use people power against formal elections that are not free and fair”.

Police were led by Siem Reap court deputy prosecutor Chhoun Sopanha, who declined to comment extensively on whether charges were being sought yesterday.

“I was with the provincial police last night to investigate the Cambodia T-shirt Printing House, and we found some proof, but I cannot elaborate,” he said, adding that the case was still under investigation.

Siem Reap deputy police chief Yek Keo said he could not say who tipped authorities off about the T-shirts.

“Last night, I went to [the] printing house after I got an order from the deputy prosecutor. But I cannot say anything about this while the investigation is still ongoing,” he said.

Council of Ministers spokesman Phay Siphan said although he had not heard about the case, the KPPM was considered a risk to national security and if the T-shirts were against “Cambodian interests” they should not be allowed to be printed.

“The constitution, all election laws, due process have to be [upheld] . . . whoever is against this, they are against the constitution, they are against the law and they jeopardise national security . . . so they could be considered a terrorist group,” he said.

The staff member said workers did not realise that what they were printing carried sentiments against the election.

“It was our fault that we didn’t look thoroughly and think deeply about what the sentence meant,” he said, adding that authorities visited the shop to determine whether it was printing the T-shirts for political purposes or simply as a commercial job.

“We really had no intention of doing this,” he said.

Ou Virak, president at the Cambodian Center for Human Rights, said that calling on people not to vote did not break any law.

“It’s nothing new actually . . . people in previous elections have always called on others not to vote . . . [It] is not incitement. Incitement is only illegal when you call for people to commit a crime . . . Voting is not mandatory [in Cambodia] . . . it’s actually a right of the population,” he said.

Although the government has been quick to go after those distributing anti-government materials in the past, the KPPM and those linked to it are particularly targeted, Virak said.

“This confiscation [of T-shirts] is illegal because the KPPM are not an illegal or terrorist group . . . there’s a lot of precedent for that [from the government] but certainly it’s not proper or legal.”