United States Ambassador William Heidt yesterday said allegations of US interference in Cambodia’s internal affairs were “absurd” and made without a “shred of serious or credible evidence”, but stopped short of speculating on any potential repercussions from the superpower.

The ambassador’s statement comes a day after Prime Minister Hun Sen lashed out at the US, calling it the “mastermind” behind jailed opposition leader Kem Sokha’s purported conspiracy to topple the government, while also warning the embassy to refrain from acting like Cambodia’s “parent”.

Ambassador Heidt spoke with local journalists at the embassy yesterday and seconded the European Union’s call for Sokha’s immediate release, while at the same time rejecting accusations – promulgated by pro-government media, as well as the premier and other officials – of US involvement in recent events.

“All of the accusations you have heard in recent weeks about the United States – every one of them – are false,” he said, reading out a written statement. “The recent press stories about Mr Sokha’s arrest have completely, and intentionally, mischaracterised what the United States is doing in Cambodia.”

While the ambassador did not elaborate on the accusations, senior Cambodian officials and government mouthpiece Fresh News have circulated unsubstantiated theories – originating with anonymous Facebook users – accusing the US of acting as a “third hand” to foment a colour revolution in Cambodia and overthrow the Cambodian People’s Party-led government.

Heidt reiterated that the US had poured around $1 billion into Cambodia over the last 24 years, while noting that during the same period Cambodian exports to the US had topped $36 billion – and were set to benefit even more from tens of millions in savings thanks to recently dropped tariffs.

“So think about it. While we are doing these things to chuoy srok khmer [save Cambodia], that in the background we have been conducting a secret campaign that lasts 24 years, through four American presidents, to undermine all that progress that we are trying to help bring about. It just makes no sense,” Heidt said.

Listing the US’s contributions in agriculture, demining efforts and cultural development, Heidt said the embassy’s recently launched “#RedHerringsKH” hashtag campaign was an attempt to promote the country’s actual contributions to Cambodia, contrary to the untruths being conveyed through the media. The hashtag takes its name from a term for deliberately misleading information.

Heidt went on to acknowledge that other countries might support the Cambodian government’s actions – an apparent reference to China – but noted that the US Embassy would continue to promote democracy.

“What concerns me, saddens me, is that Cambodia is step by step isolating itself from the international community,” he said, adding that warnings from the US, EU and others should not be ignored.

Though statements from Western governments and NGOs have been almost universally critical, China’s Foreign Ministry and a visiting diplomat have backed recent events in the Kingdom and promised to continue to support the Cambodian government.

Government spokesman Phay Siphan yesterday did not back down from the government’s line that the US was interfering in Cambodia’s affairs, and that Sokha’s arrest had been the logical response.

“The US interference in the internal affairs of Cambodia is the destruction of real Khmer democracy,” he said.

He also maintained that Heidt’s suggestion that tourists and Western companies might feel unwelcome in light of recent events was “false”, and insisted that Cambodia was committed to its sovereign and independent development of democracy.

Meanwhile, the European Parliament is set to vote on a resolution on Cambodia on Thursday. One of the drafts – proposed by the Group of the Greens/European Free Alliance, one of eight political groupings in the body – condemns Sokha’s arrest, and also alludes to a potential suspension of Cambodia’s preferential access to the European market due to other rights abuses.

Additional reporting by Leonie Kijewski