A teenager convicted of murder has posted a video online from prison, where he appears to rap about the fatal stabbing of Kayden Moy and claims he will commit violence again.

Jay Stewart, 19, and Cole Turley, 18, pleaded guilty to the murder, which occurred on Irvine Beach in May of the previous year. Both were sentenced to life imprisonment last week, with a minimum term of 16 years.

The video, reportedly filmed in a cell at HMP Polmont and shared on Snapchat, shows Stewart topless and masked. In the footage, he raps about the killing and states his intention to kill again upon his release.

The Scottish Prison Service has confirmed it is investigating the matter after an anonymous report was made. A third teenager involved in the case, who is 15 and cannot be identified due to legal reasons, received a minimum detention period of 14 years.