A Ministry of Foreign Affairs letter obtained by the Post yesterday states that a tourist e-visa issued for deported Mother Nature co-founder Alex Gonzalez-Davidson is null and void.

The April 8 letter from Foreign Affairs Ministry Secretary of State Long Visalo is addressed to the General Department of Immigration and stamped “urgent”.

It states that although Gonzalez-Davidson is blacklisted, the e-visa system was sluggish and failed to stop the issuing of the document on April 6.

“Inform immigration officials at Cambodia’s international border checkpoints not to allow [Gonzalez-Davidson] to enter Cambodia,” it reads.

Immigration Department director Sok Phal said all checkpoints had been informed. “I would like to tell him do not come . . . He will face arrest and be sent back immediately.”

Gonzalez-Davidson was deported in February 2015 but was charged earlier this year over his group’s anti-sand dredging activism in Koh Kong.

Am Sam Ath, of the rights group Licadho, said that refusing to allow Gonzalez-Davidson to appear at trial is a serious violation of his rights.

Previously, officials have maintained that the environmentalist can be tried in absentia.

Gonzalez-Davidson said he was not surprised at the cancellation and will continue to pursue his return, calling the situation “a very embarrassing episode for the government”.

Additional reporting by Alessandro Marazzi Sassoon