Human Rights Watch pressed France on Wednesday to end what it described as recurrent police violence against migrants in the northern town of Calais, where hundreds have returned despite the demolition of a sprawling camp once known as "the jungle".
In a report entitled "Like Living in Hell", the U.S.-based rights group said police routinely abused migrants in the hope of having them leave the coastal city.
Based on interviews conducted with some 60 migrants in the area, Human Rights Watch (HRW) said police had used pepper spray on child and adult migrants while they were sleeping, regularly sprayed or confiscated sleeping bags and clothing, and sometimes destroyed food and water.
"Such acts violate the prohibition on inhuman and degrading treatment as well as international standards on police conduct," HRW said.
"Local and national authorities should immediately and unequivocally direct police to adhere to international standards on the use of force and to refrain from conduct that interferes with aid delivery."
Regional prefect Fabien Sudry dismissed the report, saying the accusations were unfounded. Police force was used in a proportionate fashion, he said in a statement.
"The prefect stresses that anyone who believes their rights are threatened has the option of referring it to the relevant judicial authorities. To his knowledge, only three complaints against the police have been submitted since the end of 2016."
Aid agencies and government officials estimate there are now as many as 600 migrants in the northern port area, where a vast shanty town sheltering up to 10,000 was razed by authorities last October.
Calais provides them with a base from which to try to cross illegally to Britain, the destination of choice for many who speak English or already have family or friends in the UK.
"Since they destroyed the Calais camp last year, there is no place to sleep or eat. It's like living in hell," HRW quoted a 29-year-old Ethiopian national as saying.
The allegations of police misconduct echo what other migrants and local associations representatives told Reuters last month.
A local court in June ordered authorities to provide drinking water, toilets and showers to migrants and to allow charities to hand out meals. At the same time, it upheld government decisions to deploy extra riot police and not to build a new reception centre.
New president Emmanuel Macron last month promised migrants would be treated humanely after France's human rights watchdog was fiercely critical of the living conditions they face.