Ran Boroth (left) is escorted by a police officer at Koh Kong provincial court last month. Photograph: Heng Chivoan/Phnom Penh Post

The only man convicted in relation to a murder case that made global headlines, the killing of environmentalist Chut Wutty and military police officer, In Rattana, walked free on Friday, less than two weeks after his sentencing, rights group Licadho said.

Ran Boroth, who was found guilty of accidental killing In Rattana with Rattana’s own weapon as he attempted to disarm the deceased, who had allegedly shot Wutty moments earlier, was sentenced to two years in jail on October 22, with 18 months of that sentence suspended.

The verdict outraged rights groups, which argued Boroth was simply a fall guy who had been handed a light sentence as a political solution to the case of the high-profile killings.

Licadho director, Naly Pilorge, said that Boroth’s release – after just six months in jail thanks to time served – concluded what had been a mockery of justice from day one.

“Licadho believes that the government investigation lacked any semblance of credibility. We renew our call for a critical, independent investigation into the double murder of Wutty and Rattana and the events leading up to it,” she said in an email.

Ministry of Interior spokesman Khieu Sopheak said the case was under the jurisdiction of the Koh Kong provincial court and directed questions to officials there.

Koh Koh provincial judge Kham Sophary and deputy prosecutor Srey Makny said they were busy in a meeting and could not comment.

The court has previously defended the integrity of the trial.

After the verdict, Licadho pointed to multiple inconsistencies in the case, such as three contradictory official accounts of what happened, the failure of the court to call key witnesses and the fact that the prosecution did not even attempt to concretely prove Rattana had killed Wutty.

Wutty was shot on April 26 after a group of soldiers and military police officers stopped his vehicle during a trip to investigate illegal logging in the Cardamom Mountains in Koh Kong province’s Mondul Seima district.

Boroth was working as a security guard at the time for the firm Timbergreen, which Wutty was investigating.

The Post was unable to reach Boroth.

To contact the reporter on this story: David Boyle at [email protected]

May Titthara contributed to this report