An Afghan migrant has been jailed for life in Germany after murdering his ex-girlfriend because she ended their relationship.

The asylum seeker, identified as Ahmad S. due to German privacy laws, was found guilty of stabbing 17-year-old Mireille 14 times at her flat in Schleswig-Holstein in March last year.

The court heard how Ahmad S turned out to be 11 years older than he claimed, after he arrived in Germany seeking asylum as a minor in 2015 - arguing he was just 18.

According to the court, the Afghan migrant was jealous that she found a new boyfriend and hated that he could no longer control every aspect of her life.

Rejected Afghan asylum seeker Ahmad G. was jailed for life for murdering his girlfriend Mirielle

Ahmad S. covering his face with a file as he appeared in the district court of Flensburg in the northernmost German state of Schleswig-Holstein

Ahmad S. denied the murder in court and claimed that someone else must have committed the act.

He was found guilty on murder charges by the district court of Flensburg in the northernmost German state of Schleswig-Holstein.

He arrived in Germany in 2015 as unaccompanied minor refugee and filed for asylum - which was rejected.

Ahmad S. claimed that he is currently 18 years old, but the court had doubts and ordered an age test.

Forensic expert Sabine Gumpert testified at the start of the trial that Ahmad S. was at least 21 years old and that her examination strongly suggested he could even be 29 years old.

He convicted of murdering 17-year-old girlfriend Mireille by stabbing her 14 times because she ended their relationship

The apartment block in Flensburg where teenager Mireille was murdered in March last year

As a result, the court sentenced Ahmad S. according to adult law instead of juvenile law, which in Germany is customary for those under the age of 21 and would have barred the judges from putting him away for life.

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 that 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.

The court sentenced Ahmad S. according to adult law instead of juvenile law, which in Germany is customary for those under the age of 21