A police force at the centre of a Home Office anti-drugs pilot is disproportionately subjecting Black people to drug testing, openDemocracy can reveal.

South Yorkshire Police was one of five forces handpicked by the Home Office for additional funding to ramp up drug testing on arrest. Since 2019, it has used the tool a total of 4,819 times, according to data obtained through a Freedom of Information (FOI) request.

But Black adults accounted for one in ten of those tested, despite representing only one in 20 arrests (4%) by the force, according to Home Office data.

“This worrying disparity needs to be examined and the officers responsible asked to account for their use of powers,” said Katrina Ffrench, director of UNJUST, an organisation that challenges discrimination in policing.

“Far too often there is a lack of supervision and bad practice goes unchallenged.”

Activists also warned about the policy’s consequences, with the burden falling disproportionately on Black communities whose members are often already the subject of unfounded stereotypes regarding drug use.

Those consequences can range from imprisonment for up to three months to a fine of up to £2,500 for anyone who fails to comply with the policy – or any follow-up meetings and treatment that is mandated. Attendance is also routinely set as a condition for bail by courts after they receive a positive drug test for people held in custody.

A South Yorkshire Police spokesperson said the force and the Home Office have different ways of recording multiple arrests of the same person, making the data hard to compare directly.

They were dismissive of our findings, claiming the force’s own arrest data “provides a different view”. But despite repeated requests, that data was not shared with openDemocracy.

Nor could the force say how many tests were carried out on the basis of officers’ own discretion, which is a key concern for campaigners.

Habib Kadiri, a research manager at StopWatch UK – which campaigns for more accountable policing – said: “Once more we find a police force unwilling to seriously address the hurt and trauma they cause by allowing their officers to act upon their prejudices.”

South Yorkshire Police has recently carried out a four-week operation to further increase its use of drug testing on arrest, boasting of a four-fold increase in the first week of March alone.

Adults with Asian backgrounds also appear disproportionately affected, accounting for 5% of arrests but making up 8% of total drug tests over the three-year period.

By contrast, arrest and drug testing rates were roughly equal for white people, at 79% and 80% respectively.

In October, the government gave a total of £375,000 to police in England and Wales to expand their capacity for drug testing on arrest.

But South Yorkshire was one of five forces selected to receive an additional £32,000 to increase testing for those arrested on suspicion of a wider range of offences, like domestic abuse and public order offenders.

The scheme is part of the government’s ten-year drugs plan, which includes £15m of funding in the next four years alone.

Just £5,000 from the £375,000 total is ring-fenced for extra testing equipment and training for police officers and staff. It is unclear whether this will encompass additional training to detect and address possible racial bias.

Currently drug testing on arrest is mainly reserved for so-called “trigger offences”, such as burglary and robbery. A government white paper will also explore whether the tool can be used for recreational drug users.

Since 2019, the annual number of drug tests on arrest has decreased across several police forces in England and Wales.

In London, the Metropolitan Police and City of London Police have seen figures fall year-on-year since 2019, while forces in Gwent, South Yorkshire and West Yorkshire have plateaued or begun to increase from a pronounced drop in 2020.

On the other hand, overall arrests have increased for South and West Yorkshire and Gwent, while for the Met they have remained virtually the same for the years 2019/2020 and 2020/2021.

With the government now aiming to reverse that trend, activists have urged caution over the policy. Kevin Blowe, a coordinator at Netpol, a police monitoring group, warned that it could exacerbate racial profiling and persistent, unfounded stereotypes of “Black communities as rife with drug dealers”.

He added: “The so-called ‘war on drugs’ in turn becomes the justification for the staggering use of police stop and search powers.”

Ffrench said: “I am concerned that drug testing on arrest is being rolled out even further when so little is known about it. We have to make sure the policy is both proportionate and necessary,” adding that more data and public debate is needed to better understand the policy.

But FOI responses confirmed that the government is not collecting drug testing data centrally, meaning any evidence of racism may only be picked up locally.

A spokesperson for the Home Office said: “Nobody should be tested because of their race,” claiming the tool would enable “individuals to access the treatment and other support they need”.