The deputy leader of far-right group Britain First has been arrested in London over a speech made at a rally in Belfast this summer.
Jayda Fransen, 31, from Penge in south-east London, was arrested in Bromley by Police Service of Northern Ireland (PSNI) detectives on Saturday.
Britain First leader Paul Golding, in a video posted on his Twitter feed, said Ms Fransen will be taken to Belfast to be interviewed over comments she made outside the City Hall in August.
He said: “A large group of plain clothes police detectives from Belfast of all places jumped out of nowhere and have arrested Jayda.
“What have they arrested her for? Both of us addressed, made a speech, at a public demonstration outside Belfast City Hall all the way back in August.
“The detective I spoke to told me she is being flown to Belfast tonight to be interrogated.
“It's absolutely ridiculous - this is non-stop with me and Jayda, non-bloody stop.”
He said his colleague had been arrested for “no bloody reason”.
Ms Fransen and Mr Golding were in Belfast on 6 August for a demonstration by around 50 people calling themselves Northern Ireland Against Terrorism, which took place on the same day as a republican march organised by the Anti-Internment League to mark the use of detention without trial by the British Army during the height of the Troubles in 1971.
A PSNI spokesman said: “A 31-year-old woman has been arrested by PSNI Criminal Investigation Branch Detectives in London today.
“The arrest was made in Bromley by PSNI detectives working with officers from the London Metropolitan Police Service.
“The woman is being brought to Belfast to be interviewed under Art 9(1) of the Public Order (NI) Order 1987 in relation to speeches made at the Northern Ireland Against Terrorism Rally on Sunday 6th August this year.”