Clare Rewcastle Brown, an activist journalist who runs a website and radio station fiercely critical of chief minister of the Malaysian state of Sarawak, Taib Mahmud, said she was deported to Singapore on arrival at the airport yesterday.
Brown, who this year won an award from the International Press Institute for her work, said she arrived at Sarawak's Kuching International Airport from Singapore and was issued a notice of refusal of entry by immigration authorities.
The activist journalist, who was born in Sarawak but lives in Britain, said the suit was brought by "a transnational corporation that is on the British and European stock exchanges," and by powerful figures within Sarawak.
"I came in an attempt to defend myself in this case. But I was informed that I've been put on the blacklist and not allowed to enter Sarawak," she said in a video interview.
She accused authorities of barring her so that she could not defend herself in the case.
"The fact that I am threatened with being turned away by the Immigration shows exactly how this country is run for the benefit of the sorts of people who are trying to sue me," Brown said.
She became a journalist, joining the BBC World Service in 1983.
Switzerland-based forest-protection group the Bruno Manser Fund called on British premier David Cameron to raise the matter personally with visiting Malayian premier Najib Razak.