Christopher Kapessa's body was found in the River Cynon near Mountain Ash, Rhondda Cynon Taff on 1 July 2019.

In February, the CPS concluded that although there was sufficient evidence for a prosecution for manslaughter it was not in the public interest to proceed.

The family appealed the decision under the CPS's Victims' Right to Review scheme, which allows victims to request that a prosecutor, not previously involved in the case, re-examine the case to ensure the correct decision was made for the right legal reasons. On Monday the CPS said the prosecutor had upheld the earlier decision, maintaining that the 14-year-old boy who pushed Christopher, 13, into a river before he died did so as a foolish prank.

The review found the push amounted in law to a common assault and was therefore an unlawful act. It also found the push resulted in Christopher's death and so there was a "realistic prospect of conviction for manslaughter". But it maintained a prosecution would not be in the public interest.

Jenny Hopkins, who oversees the appeals and review unit within the CPS, said: "Although there was evidence to support a prosecution for manslaughter it was not in the public interest to prosecute. Christopher's tragic death occurred after a group of children went out to have fun by the river. The evidence showed that Christopher was pushed into the river as a foolish prank with nothing to suggest that the suspect intended to harm him, although that was the awful consequence."

She said the "principal aim of the youth justice system is to prevent offending and there is no suggestion that the suspect would commit further offences" and they had considered the young age of the suspect, his lack of a criminal record and otherwise good character.

The welfare and impact on Christopher's friends who may be called to give evidence and have to relive the death of their friend was also considered, she said.

Concluding, she said: "The factors militating against a prosecution outweighed the factors in favour of a prosecution. We recognise our decision will be upsetting for the family who may feel the suspect's life has been prioritised over Christopher's... We have applied our legal test to the evidence and I hope they can understand how and why we came to the decision."

Christopher's mother Alina Joseph said: "The decision taken by the CPS not to prosecute those responsible for the death of my son goes against all the principles of equality and justice and the inequality that many campaigners have fought to eradicate for many years. I keep hoping for justice but it seems that I have to fight for it at every given step and turn."

The Christopher Kapessa Family Justice Campaign described the review decision as "perverse" and "not simply a gross injustice given the facts of the case but represents a damning landmark for Criminal Justice Agencies for Wales and the rest of the United Kingdom." It added: "It considered a black child's life cheaper than the public interest afforded to the suspect." and said Ms Joseph was considering lodging a judicial review against the CPS' decision and seeking a personal intervention of the Justice Secretary through her MP.

Christopher's family also made a complaint to the police watchdog, the Independent Office for Police Conduct (IOPC), about how South Wales Police managed the investigation.