Facebook has removed a number of Justice for George Floyd groups for exhibiting “inauthentic behaviour”.
BBC News had highlighted some suspicious groups had switched their focus to call for justice for the black man killed in police custody.
Some, run by accounts seemingly based in Vietnam or Bangladesh, had posted misleading images.
And others had previously focused on coronavirus, 5G conspiracies and support for US President Donald Trump.
A Facebook spokesman said it had “removed the vast majority of them, for violating our policies”.
There has been a surge in membership for Facebook groups supporting the Black Lives Matter movement, following the protests sparked by Mr Floyd’s death, on 25 May.
But for some it is unclear what the motives of their administrators are.
In some cases, they could be exploiting the movement to gain followers and/or stoke tensions.
Some of the profiles based outside the US had frequently posted inflammatory images and videos before Facebook intervened.
One group, Justice for George Floyd, had almost 2,000 members.
Set up in March, it originally focused on the coronavirus but later that month switched to “US breaking news”, featuring stories sympathetic to the US president, before turning to Black Lives Matter.
In its final incarnation, two administrators – identified as in Vietnam – had repeatedly shared posts critical of the protesters, including images of battered police cars that predate the current protests.
Another group, Justice For George Floyd & Latest Updates, was run by a profile claiming to be based in Bangladesh.
The administrator’s profile photos had all been copied from other websites and included images of celebrities and animals.
And it used highly emotive language in contradictory posts that supported both the police and the protesters.
This would not be the first time Black Lives Matter groups have been hijacked.
Investigations into foreign interference during the 2016 US presidential election accused Russia of being behind a misinformation campaign that had taken advantage of the movement.
However, no evidence has been presented to indicate Moscow is involved this time.