West Midlands Police could face legal action over hundreds of cameras put up in largely Muslim areas of Birmingham.
More than 200 covert and overt cameras were installed in Washwood Heath and Sparkbrook, paid for with government money to tackle terrorism.
The force said the covert ones had been removed after uproar from residents.
Human rights lawyers said they would apply for a judicial review of the camera installation action unless there was a guarantee to remove all of them.
The £3m scheme, called Project Champion, involved cameras being put up by the Safer Birmingham Project (SBP), made up of the city council, police and agencies in the Washwood Heath and Sparkbrook districts.
They can record pictures and number plates of every car that goes in or out of the areas.
Residents said there had been no consultation about their introduction and were also angry after learning where the funding had come from.
Last month Chief Constable Chris Sims apologised after an independent report into what happened said the force showed "little evidence of thought being given to compliance with the legal or regulatory framework" before the cameras were put up.
It also found the lack of transparency over their installation "significantly undermined" police trust and set back relations by almost 10 years.
Mr Sims said none of the cameras had ever been used and the remaining cameras had been covered with bags until after discussion with a new project board with a "strong community representation".
But human rights group Liberty said it wanted assurances all the cameras would be removed, otherwise it said it would pursue legal proceedings in the High Court.
In a statement, Liberty said the force must acknowledge the decision to install the cameras was unlawful and breached residents' right under Articles 8 and 14 of the European Convention on Human Rights.
Corinna Ferguson, legal officer with Liberty, said: "It is baffling that West Midlands Police are still trying to salvage this unlawful discriminatory scheme.
"These cameras are useless for everyday policing and must be removed immediately if badly damaged relations are to be repaired."
West Midlands Police said it had received a letter from Liberty stating its intention.
"The project board, made up of police, Birmingham City Council, elected members and independent community representation, has not yet made any decisions in relation to the remaining cameras," a spokesman said.