Four other staff members said on Twitter on Monday they had resigned including Brendan O'Byrne, who said the new management had ordered him to remove the online version of the report about the sale of the newspaper.
Hun Sen, the world's longest serving prime minister, and his government already stand accused of a sweeping crackdown on the independent media, rights activists and opposition politicians in what appears to be an effort to cling to power in the upcoming poll.
BANGKOK, May 7 (Reuters) - The purchase of the Phnom Penh Post by a Malaysian whose public relations firm lists Cambodia's long-serving Prime Minister Hun Sen as a client is a "disaster" for media freedom ahead of a general election, an worldwide rights group said on Monday.
The newspaper's editor-in-chief Kay Kimsong was reportedly fired after he refused to take down the news story.
"The Supreme Court upheld the Appeal Court's decision", said lawyer Pheng Heng. The Australian said the paper had been "remarkably" free from government interference.
Sam Rainsy, the former leader of the opposition party, who abruptly quit previous year in the face of government pressure, said that The Post had recently published two of his letters to the editor, but that he did not expect the new management to continue the practice.
Cambodia has elections in July.
"Our article was written in an attempt to maintain the transparency and integrity of our paper as we have done for more than 25 years", they wrote.
Phil Robertson, the deputy Asia director at Human Proper Watch, mentioned the sale of the Phnom Penh Put up means "the final pillar of press freedom has been toppled in Cambodia".More news: MP resigns in wake of High Court ruling
A counter statement was then released by Sivakumar, where he called the Post's editorial a "disgrace that "borders on internal sabotage" and expressed 'serious doubts" about the calibre of journalists at the paper.
Huy Vannak, an Interior Ministry official, said that the prime minister was "too busy doing the affairs of the nation" to concern himself with the sale of a newspaper, adding that he was unaware of any prior business relationship between Hun Sen and Sivakumar's company.
Bill Clough, the former owner and publisher of the Phnom Penh Post, said in a video published past year that he wanted to maintain the paper's independence.
Ganapathy's company website lists "Cambodia and Hun Sen's entry into the Government seat" as a former "project".
But Sophal Ear, the analyst, said he saw the language about obeying laws as "a signal to the authorities" about the newspaper's future.
Following in the footsteps soon after, was The Post's former publisher Marcus Holmes, managing editor Stuart White, web editor Jenni Reid and senior editor Michael Dickison.
All stories must now be approved by Purushotman in what critics of the sale, and subsequent events, have said is a further worrying sign that the Post's independent voice has been silenced.