When Wyn Ellis was stopped at Suvarnabhumi airport, immigration officials showed him a 2009 letter in which he was described as a ‘danger to Thai society’. Photograph: Wyn Ellis
When Wyn Ellis was stopped at Suvarnabhumi airport, immigration officials showed him a 2009 letter in which he was described as a ‘danger to Thai society’. Photograph: Wyn Ellis

Thailand has freed a British academic and long-term resident who was detained at Bangkok airport for four days after his name showed up on a national blacklist as posing a threat to national security. Wyn Ellis’s detention appeared to relate to a six-year-old dispute in which he proved that the former director of the Thai agency responsible for promoting intellectual property rights had plagiarised his PhD thesis on asparagus cultivation.

An agricultural consultant who has worked with the UN’s environmental programme, Ellis had already won legal battles against Supachai Lorlowhakarn after an investigation found that 80% of his thesis had been taken from various sources. Supachai had his doctorate rescinded. But when Ellis was stopped at Suvarnabhumi airport on Thursday, immigration officials showed him a 2009 letter in which Supachai describes him as a “danger to Thai society”.

The ordeal appears at best to be a failure to update the blacklist and at worst an example of the continuing ability of powerful figures in Thailand to target their enemies by exploiting the legal system. While he was detained, Ellis was allowed to access the internet. On Monday, he told the Guardian that his wife spent all morning at the immigration bureau to no avail. “The prospects for my immediate release seem dim,” he said.