Canadian far-right activist Lauren Southern tweeted Monday that she had been denied entry into Britain, as authorities there moved against the well-known YouTube personality and two other activists.

The Daily Mail reported that Southern, 22, was quizzed Monday by U.K. border officials in the French port of Calais as she prepared to travel to the U.K., where she was to interview Tommy Robinson, the controversial co-founder of the far-right English Defence League.

The Mail said Southern was taken aside over concerns about an incident in the English city of Luton last month, in which she allegedly distributed racist, anti-Islamic material.

Southern is one of three far-right figures who say they have been denied entry to Britain in the past 72 hours after they were detained when trying to enter. The others are Austrian Martin Sellner of the Generation Identity group and American commentator Brittany Pettibone.

The Mail reported that before Southern’s apprehension, Sellner and Pettibone were halted by border police on Friday when they got off a plane at Luton Airport.

Southern, who has more than 400,000 subscribers on YouTube, tweeted that she was “officially banned from UK for ‘racism”‘ but was doing fine.

In a video posted to YouTube on Tuesday, Southern appears on camera with the EDL’s Robinson in Calais.

In the clip, she repeats that she has been “officially banned from the U.K. for ‘racism’ and now I’m stuck in Calais.”

She goes on to say that U.K. officials told her she was being questioned under anti-terrorism legislation.

She said she was asked about a speech she gave in Belgium for a nationalist group, was quizzed on her political ideology, and was also asked about religion and whether she was a Christian extremist.

“They said, ‘how do you feel about someone driving a car or a truck into a group of people, a group of Muslims?’ Particularly, they singled out Muslims,” Southern said of the U.K. officials. 

Britain’s Home Office said in a statement that the border force “has the power to refuse entry to an individual if it is considered that his or her presence in the U.K. is not conducive to the public good.”

Southern also tweeted a pamphlet she said she was given by officers with the U.K.’s Kent Police, which indicates she was indeed halted under Schedule 7 of the Terrorism Act of 2000.

Meanwhile, Sellner said in a video posted on Twitter that he and Pettibone were detained for three days and were then deported.

He said on the video that both of them were handcuffed. He said he had planned to give a speech at “Speakers’ Corner” in London’s Hyde Park. He said “that was my crime.”

Pettibone said that she, too, was denied entry because she had plans to interview the EDL’s Robinson.

She said from Austria that “It felt like they were saying, ‘you’re right-wing, that’s not allowed.”‘