PHNOM PENH (Reuters) - The sister of a missing Thai pro-democracy activist presented evidence to a Cambodian court on Tuesday that she said showed her brother was in the capital Phnom Penh at the time of his alleged abduction by unknown gunmen. Wanchalearm Satsaksit, 37, was bundled into a vehicle in front of his Phnom Penh apartment in June, New York-based Human Rights Watch said. Cambodian police have previously said they were unaware a kidnapping had taken place. After attending a hearing at the Phnom Penh Municipal Court, Wanchalearm’s sister, Sitanun Satsaksit, told reporters it was up the Cambodian judiciary to investigate further. “We had sufficient evidence to show to the judge that Wanchalearm was here in Phnom Penh and the abduction also happened here in Phnom Penh,” she said. A judge will decide whether there is enough evidence to proceed with the case. Wanchalearm was speaking on his mobile phone to Sitanun when he was abducted, the elder sister has said previously. After holding a Buddhist prayer ceremony for her brother last week, Sitanun said she planned to submit photographs and videos to the court show that Wanchalearm was in the city. Amnesty International urged Cambodian authorities on Tuesday to redouble efforts to look into Wanchalearm’s disappearance, saying the investigation had “moved at a snail’s pace and key evidence appears to have been ignored.” “The Cambodian authorities need to show that they are undertaking a credible investigation,” said Yamini Mishra, Amnesty International’s Asia-Pacific Regional Director. Cambodian national police spokesman Chhay Kim Khoeun, who had previously said police were unaware of the incident, on Tuesday said authorities were working on the case, but declined further comment. At least eight other Thai activists who fled the country after a 2014 military coup have disappeared from Laos, Cambodia and Vietnam, with some later found dead, associates and rights groups say. Thai authorities have said they had nothing to do with the disappearances.