Clare Rewcastle Brown, an investigative journalist and sister-in-law of former British PM Gordon Brown, was refused entry into the Malaysian state of Sarawak on Wednesday.

Brown, an activist who spear-headed anti-corruption campaigns Sarawak Report blog and Radio Free Sarawak in the state, was denied entry by the immigration officials after she landed at the Kuching International Airport from Singapore at 1.15 pm on Wednesday. The officials said she was on a travel blacklist list and put her back on a plane to Singapore. She was on a blacklist since 2011.

Through her campaigns, the 53-year-old journalist had strongly criticised Chief Minister Taib Mahmud's 30-year rule that plunged the state into poverty.

Brown had arrived in Sarawak regarding to civil suit that was filed by an unnamed company against her.

In a video posted on YouTube, the Sarawak native lashed out at the Malaysian authorities accusing them of trying to prevent her from defending her case in the civil suit.

"How can I have a fair trial in these circumstances?" she said in the video. "The fact that I am being threatened with being turned away now by immigration shows exactly how this country is being run for the benefit of the sort of people who are trying to sue me now."

A Malyasian official told AFP on Brown being listed in the refusal list that, "The state government doesn't really give any reason. If they don't like this person, what can we say?"

Brown's deportation took place at a time when British Prime Minister David Cameron was scheduled to hold talks on investment with Malaysian Prime Minister Najib Tun Razak. Cameron is expected to raise the issue with his Malaysian counterpart, who is on a four-day official tour to the UK.

Brown's campaigns had often raised alarm with Malaysian authorities over her consistent efforts to highlight the abuse of power and corrupt practices by the ruling government. Chief Minister Taib has been accused of mass corruption and misuse of natural resources in the island state.

The Malaysian Anti-Corruption Commission (MACC) was given the responsibility of investigating Taib's alleged corrupt practices in 2011. However, the commission was accused of inaction against Taib even after two years of the probe by Global Witness, an international watchdog.

"The MACC seem either powerless or are recalcitrant in bringing some of the serious allegations against Taib [Mahmud] to a satisfactory conclusion. It appears clear to all that he is being protected by the powers that be," said Ambiga Sreenevasan, co-chairperson of Malaysia's Coalition for Clean and Fair Election, reported The Independent.

Continuing with her anti-Taib stance, Brown said, "He's the tail that wags the dog in Malaysia at the moment, and he runs the state [of Sarawak] as a private business,...if it wasn't for the votes that he is able to deliver through his strongman tactics, Najib [Najib Razak, Malaysian Prime Minister] wouldn't be in power."