Two activists from the conservation group Mother Nature were found guilty on Friday of “incitement to commit a felony” and making unauthorised recordings of a person “in a private place” by the Koh Kong Provincial Court for their work documenting alleged sand transportation off the coast.

Hun Vannak, 35, and Dem Kundy, 21, were handed one-year prison sentences, with seven months suspended, and are expected to be released on February 13, according to their lawyer Sam Chamroeun. They have already served nearly four and a half months in prison. They were also each fined 1 million riel (about $250).

The pair was arrested in September for photographing boats they suspected were carrying silica sand off the coast of a special economic zone belonging to ruling party Senator Ly Yong Phat. The original complaint against them was filed by the chief of staff of Yong Phat’s LYP Group, Chan Nakry, who could not be reached yesterday.

Though they were taking photographs from their own boat on the open water about 1 kilometre from the alleged sand-bearing vessel, Vannak and Kundy were found guilty of making recordings of a person on private property – a decision that rights group Amnesty International called “farcical”.

In the courtroom on Thursday, Nakry’s lawyer, Chun Socheat, argued the pair had “incited” society by accusing the company of foul play by taking photographs and posting them to Facebook. Though they were documenting the alleged sand transportation in order to then post on social media, they had not done so before they were arrested.

“I cannot accept it, as I said since the beginning, that the arrest, the charge, detention and trial of my clients came as the court had great confusion over the facts and legal basis,” Chamroeun said, adding that he will discuss with the pair whether or not they decide to appeal.

Read more: How Mother Nature duo followed their principles into activism — and a trial

Reached on Friday, Kundy’s mother, Duong Saktheary, said that she was pleased at the possibility of her son’s imminent release, but disappointed with the verdict.

“I am happy that my son will be released soon. But it is not justice for my son because he did not do anything wrong,” she said.

Mother Nature co-founder Alex Gonzalez-Davidson said in an email the verdict “was completely expected”, especially given the more than four months the activists had already spent in pre-trial detention.

“Dropping charges and finding them innocent after having them jailed for such a long time would have been in a way an admission on the part of the court that the incarceration was arbitrary and thus unlawful, which is of course something they would never do,” he said.

“My take is that the same people who were behind the charges and jailing now feel as if the message – stop doing those videos, stop criticizing the government and our corporate friends – has been sent and that there is no more benefit in keeping [those] guys in jail any longer.”

Mother Nature, which is still active despite recently removing itself from the Interior Ministry’s NGO registry, has documented sand dredging and its environmental impacts for years, and recently published figures showing that more than $30 million in sand exports to Taiwan were unaccounted for in government records.

Those findings were released just before Vannak and Kundy’s arrest off the shores of land belonging to Yong Phat, who has previously been listed as a director for Silica Service Cambodge Co Ltd, one of two companies permitted to export silica sand.

Naly Pilorge, the director of local rights NGO Licadho, called the convictions for Vannak and Kundy’s environmental work “shocking”.

“How can we move into the future if corporate accountability is criminalized?” she asked in a message.