The British government is facing a court challenge over its use of child spies

Lawyers for the charity Just for Kids Law argue that the use of child informants could subject them to "severe" harm.

(CNN)The UK government is facing a court challenge over its use of children as spies in criminal investigations, as lawyers for a children's charity accused it of causing minors "severe physical and emotional harm."

Just for Kids Law said the use of minors as "covert human intelligence sources" (CHIS) without adequate safeguards violates national and international human-rights laws, including the United Nations Convention on the Rights of the Child. A hearing was held Tuesday in the charity's case against the Home Office.
Caoilfhionn Gallagher, representing the charity, cited a case raised in the British Parliament in October in which police asked a 17-year-old girl to spy on a man, subjecting her to sexual exploitation.
    "While deployed, she continued to be exploited by him and the papers suggest she was even coerced into being an accessory to murder," Gallagher said, according to the British Press Association (PA).
    UK legislation permits the use of children as spies by police and other authorities, but an assessment of the risks involved must be carried out. Authorities must determine that "risks identified in it are justified" and "have been properly explained to and understood by the source."
    Gallagher fears children could be increasingly used as spies in what she described as "the most grave and dangerous contexts," the PA reported. Children could be employed in investigations into terrorism, gang violence, child sexual exploitation and drug offenses, the lawyer said in a written submission.
    "Given that young people are increasingly involved, both as perpetrators and victims, in serious crimes ... there is increasing scope for juvenile CHIS to assist in both preventing and prosecuting such offences," Ben Wallace, Minister of State for Security and Economic Crime, said in a letter last July to the House of Lords.
    In a statement to CNN, Wallace said: "Juvenile covert human intelligence sources are used very rarely and only ever when it is necessary and proportionate and when there is no other less intrusive way to get the information needed to convict criminals or terrorist suspects."
    "Their use is governed by a strict legal framework and is overseen by the Investigatory Powers Commissioner. Throughout any deployment and beyond, the welfare of the young person is the paramount consideration," he said.
    In response to a request from a member of Parliament, Adrian Fulford, the Investigatory Powers Commissioner, confirmed in a March 2019 letter that 17 children had been authorized for use as spies since January 2015. One was 15, while the others were 16 or 17.
    "Overall, the low numbers show that this tactic is only utilised in extreme circumstances and when other potential sources of information have been exhausted," Fulford wrote.
    James Eadie, representing Home Secretary Sajid Javid, said at Tuesday's hearing that the use of minors as informants "may be very important for reasons of national security, public safety, and the prevention of disorder and crime," according to PA.
      The aim of the CHIS program "is to ensure that use is properly controlled and accompanied by appropriate decision making," Eadie said. "To that end, the welfare of the child is placed at the forefront of decision making as to the deployment of CHIS and the scheme provides adequate and appropriate safeguards."
      Judge Michael Supperstone will rule on the legal challenge at a later date, PA reported.