The minimum terms handed to Britain’s youngster knife murderers for killing Shawn Seesahai are set to be reviewed by the Court of Appeal after claims the sentences were unduly lenient.

The boys, now aged 13, were both 12 when they attacked Mr Seesahai with a machete on playing fields in Wolverhampton on November 13 last year.

They were both convicted of murder in June and were each ordered to serve life sentences with a minimum term of eight-and-a-half years at Nottingham Crown Court in September.

Shawn Seesahai was visiting Wolverhampton with friends (Family handout/PA)

High Court judge Mrs Justice Tipples had previously ruled that the defendants should be protected by anonymity orders, saying their welfare outweighed the wider public interest in open justice and unrestricted reporting.

In a statement confirming that the sentencing of the boys is set to be reviewed, a spokesperson for the Attorney General’s Office said: “These sentences have now been referred to the Court of Appeal under the Unduly Lenient Sentence scheme.”

The scheme allows relatives, victims and members of the public who believe sentences are unreasonably low to ask the Attorney General’s Office to review cases relating to a number of specific serious offences, and consider whether they should be sent to the Court of Appeal.

Mr Seesahai was stabbed through the heart and lungs, and suffered a skull fracture on Stowlawn playing fields, with one of the wounds he suffered almost passing all the way through his body.

His killers were described during their sentencing as “the youngest knife murderers” and are believed to be the youngest defendants convicted of murder in the UK since Robert Thompson and Jon Venables, both aged 11, were found guilty in 1993 of killing two-year-old James Bulger.

Passing sentence, Mrs Justice Tipples told Mr Seesahai’s killers: “What you both did is horrific and shocking. You did not know Shawn. He was a stranger to you.

“You both killed Shawn in an attack which lasted less than a minute when he asked you to move (from a park bench).

Police at the scene a day after the attack (Stephanie Wareham/PA)

“I am sure from the injuries Shawn suffered that you intended to kill him. Shawn did not deserve to be attacked. Shawn did not deserve to die.

“Shawn’s parents, sister and friends did not deserve to lose him from their lives and to suffer the never-ending grief, pain and loss you have caused them.

“It is clear that the sentence I have decided to pass cannot make that right. What you did in those few moments has also changed your lives for ever.

“You will both have to live with the consequences of what you did for the rest of your lives.”

The judge added she could not be sure which of the boys had inflicted a 23cm-deep wound with the machete.

In a victim impact statement read to the sentencing hearing, the family of 19-year-old Mr Seesahai, who was living in Birmingham, said they are haunted by thoughts of how scared he must have been when he was killed.

Relatives of Anguilla-born Mr Seesahai described his murder as tragic, unexpected and senseless, and having been committed “for no reason at all”.

Both boys pleaded not guilty to murder, blaming the other for inflicting four wounds with the machete.

One of the youths admitted possession of the knife prior to the trial, while the other was found guilty of the same charge when they were both unanimously convicted of murder on June 10.