The mother Henry Nowak’s killer has been jailed for three years for removing the murder weapon from the scene of the crime.

Vickrum Digwa used a 21cm (8in) blade to kill the 18-year-old student, who was walking home from a night out in Southampton on 3 December. He was jailed for life in June with a minimum of 21 years.

Kiran Kaur, 53, of St Denys Road, Southampton, was found guilty at Southampton Crown Court in May of assisting an offender.

Judge William Mousley KC told Kaur at her sentencing “a responsible parent would have challenged their son” and have asked their child to “do the right thing”.

“You took the knife and put it at home with other weapons in your son’s bedroom,” he told her.

By putting it among “a larger collection of ceremonial and other weapons” it would have “helped to conceal what it had been used for” because she wanted him “to avoid being caught”, the judge said.

Digwa gave the knife to his mother and it was later found by police at their family home along with more than 20 other weapons.

Prosecutor Nicholas Lobbenberg described her actions as “criminality of the highest order” and her role as “crucial” when it came to removing the knife.

He told the court it was not found by police until seven days after the attack took place.

But defence barrister Mark Watson called it a “spontaneous act carried out in a matter of moments” and an “instinctive desire to protect her child”.

Kelly Newman, of the Crown Prosecution Service, said after the sentencing: “Those who seek to help murderers evade justice should be in no doubt that they too will be held accountable for their actions.”

Nowak was handcuffed by police as he lay dying at the scene after Digwa lied, claiming he had been racially abused by the teen and had acted in self-defence.

He told officers his turban had been knocked off and that he had been injured.

Bodycam footage released by Hampshire and Isle of Wight Constabulary, with the family’s permission, showed officers arriving at the scene and speaking to Digwa and others.

Nowak, who is seen on the ground in the video, can be heard saying “I’ve been stabbed” and “I can’t breathe” multiple times.

The footage shows officers turning Nowak onto his side and handcuffing his hands behind his back, and after a couple of minutes he becomes unresponsive.

An officer proceeds to tell him he is under arrest for assault.

Two police officers are being investigated for potential gross misconduct.

In a statement read outside court in June, Henry’s father Mark Nowak compared his son’s “inhumane and degrading” treatment by police, to the “decency” officers showed his murderer.

Hampshire police has apologised to the Nowak family for the way Henry was treated by its officers.

Nowak, from Chafford Hundred in Essex, was a first-year student at the University of Southampton. He had been walking back to his accommodation after drinking to a level that was below the drink-drive limit, the trial heard.

The prosecution said he was stabbed five times, including twice in the back of his legs, once in the face and a fatal wound to the chest.

Digwa said he carried the blade as part of his Sikh faith, though the Sikh Federation said the blade he used was not a religious knife, known as a kirpan.

A transcript obtained by the BBC recorded in the back of a police van has Digwa admitting to his brother, Gurpreet, that he had stabbed the teenager multiple times.

Digwa, his brother and his father have pleaded not guilty to multiple weapons offence charges.

Protests erupted in Southampton after the police bodycam footage was released.

More than 20 people have so far been sentenced over the disorder, during which 12 police officers and a police dog were injured.

The attorney general’s office has since referred Digwa’s sentence to the Court of Appeal under the unduly lenient sentence scheme. Digwa himself is seeking to appeal against his conviction and sentence.

A full inquest into Henry Nowak’s death is due to be held in Winchester next year.