Malaysia has blocked access to a whistleblowing website run by a British journalist which has reported allegations that money linked to a state investment fund ended up in Prime Minister Najib Razak's bank accounts. The Sarawak Report, founded by Clare Rewcastle Brown and based in London, has in recent months reported extensively on a series of sensational bribery and financial mismanagement allegations linked to Najib and the fund, 1Malaysia Development Berhad (1MDB) Rewcastle Brown, who is married to former British prime minister Gordon Brown's younger brother, set up Sarawak Report in 2010, and most of its reporting has focused on deforestation in the Malaysian part of Borneo - including the state of Sarawak - and corruption The move to block Sarawak Report came two weeks after the website first reported on how investigators probing the debt-laden 1MDB discovered that some US$700m allegedly made its way into Najib's personal bank accounts. The Wall Street Journal reported a similar story, citing official documents. Najib, facing mounting calls to resign, has denied receiving money for his personal use. The Malaysian Communications and Multimedia Commission, the country's internet regulator, confirmed late on Sunday it had blocked Sarawak Report for reporting on what it called "unverified content". "Such content could create unrest and threatens national stability, public order and economic stability," the commission said in a statement. It said the website would be blocked until an official investigation into 1MDB is completed. No time frame has been given for the investigation. Sarawak Report continues to be accessible from outside Malaysia, however. Responding to the decision, Rewcastle Brown - who was denied entry into Malaysia in 2013 - said it was "a blatant attempt to censor" Sarawak Report's exposure on corruption in Malaysia, ruled by the long-dominant National Front coalition since gaining independence from Britain in 1957. "This latest blow to media freedom only brings further discredit upon the present administration, who have proven unable to counter the evidence we have presented in any other way," she said in a statement sent to the Guardian. She said the move showed Malaysian authorities were fearful of being exposed, and vowed not to be silenced. "Sarawak Report will not be impeded in any way by this action in bringing out future information as and when its investigations deliver further evidence." The decision to block the site has also sparked condemnation from Malaysians, who said the government has gone back on a promise not to censor the internet. Malaysia pledged not to restrict the internet when it set up the "Multimedia Super Corridor", Malaysia's answer to Silicon Valley, in the 1990s in a bid to attract foreign investors. "Imposing stricter internet controls over what a user can post and read will severely restrict the freedoms of expression and the right to information, " Shamini Darshni, Amnesty International Malaysia executive director said. The internet regulator has previously threatened Malaysians with jail for spreading parodies or false news through social networking sites over the latest allegations against Najib.