A teenage migrant who stabbed a refugee aid worker to death with a kitchen knife could be eligible for compensation for time spent in prison after judges ruled he acted in self-defence.

The knifeman, named only as 18-year-old Afghan migrant Seyed M. due to German privacy laws, was accused of manslaughter after 20-year-old Jose M. died in a park in Ochtrup, north-west Germany, last May in a row over a girl.

Jose M. was knifed six times - including once in the heart - with the knife the defendant kept hidden in his clothing.

Jose had confronted Seyed M. after the Afghan reportedly became obsessed with a female friend of the victim, and constantly stalked her despite her pleas to be left alone.

The Afghan was already facing deportation proceedings when he bumped into Jose in the park while carrying a five-and-a-half inch kitchen knife.

Accused: Seyed M. allegedly stabbed Jose M. six times with a 5.5-inch bread knife but judges ruled he had been acting in self-defence after the aid worker punched him

But last week, a juvenile court in the nearby city of Munster acquitted Seyed M. after the judge said that the act was carried out in self defence.

Judge Michael Beier said that because Jose was bigger than the defendant, had taken boxing lessons and punched Seyed M. first, the defendant could claim self defence.

He said: 'The defendant was physically inferior (...) A kitchen knife may be carried under weapons legislation, even if it is socially and ethically questionable.'

Court spokesman Dr Steffen Vahlhaus has confirmed that both the public prosecutor's office and the victim's relatives as co-plaintiffs have filed an appeal.

The case will now be transferred to the Federal Court of Justice in the southern German city of Karlsruhe.

Stabbed: Jose M. was killed in May last year in what was allegedly a row over a girl

The Supreme Court will re-examine the evidence and rule on whether the Munster court's decision was correct or not.

If the Federal Court of Justice dismisses the appeals, it would mean that Seyed M. will be able to claim compensation for the time he spent in remand from May 21 until December 21.

Jose's mother Maria said after the initial judgement: 'The reasons the judge gave for self-defence are laughable.

'As a mother, I feel like I have done something wrong. I always told my children that knives are weapons. Watch out, you can cut yourself and you can hurt somebody with it. That's why my son did not carry a knife.'

Maria said that the judge's comments could lead to 'every person carrying a kitchen knife because it is not (legally considered) a weapon'.

She also hopes that the Karlsruhe court will look into her claim that the wrong court might have ruled on the defendant's case.

She said: 'The judge did not even want to know how old the culprit was.

'Just imagine if he was over 21, then this judge would have had nothing to say about it. It would have taken place at the wrong court.'

Seyed M. was put on trial under juvenile law which is customary in Germany for those under the age of 21, but if her claim is accepted and looked into and it turns out that he is older, the case would most likely have to be retried in an adult court.

Prosecutors at the court in Münster had demanded a three-year jail sentence but judges ruled Seyed had been defending himself.

The court heard Jose had first punched the Afghan in the face, and judges concluded Seyed had acted in self-defence.

Jose's mother, Maria, claimed that defendant Seyed M. was older than 18 and so should be tried as an adult

Judges said Jose had put the younger man in a 'headlock' and that Seyed had initially used the glass bottle as a 'milder' way to resist the attack.

Jose had wanted to become a teacher and was a member of the town's youth parliament, she said.

In recent years, a growing number of Afghan migrants have been caught lying about their age when they first entered Germany in the hope of securing a better chance of asylum.

The most high-profile case was Hussein Khavari who was jailed for life for the rape and murder of 19-year-old student Maria Ladenburger, the daughter of a high-ranking EU official.

Khavari claimed he was a minor but an expert found him to be 'at least' 22.

His father later gave evidence testifying that his son was actually 33, allowing the courts to finally sentence him as an adult.