N-Dubz rapper Dappy has called for the killer of of headteacher Philip Lawrence to be freed from jail in the video for his latest single.
During the opening credits of Tarzan 2, which has been viewed by more than 225,000 people on YouTube, the message "Free Leo Chindamo" appears among a list of other names.
Chindamo was jailed for life, with a minimum sentence of 12 years, after stabbing the 48-year-old teacher outside St George's Roman Catholic School in Maida Vale, west London, in 1995 as he tried to protect a pupil from attack.
The self-confessed leader of an armed gang later boasted of the murder in an amusement arcade.
Chindamo was originally released on licence in July 2010 after serving 14 years, claiming he would spend the rest of his life "atoning" for his crime.
But he was sent back to jail last year after breaching the terms of his licence. It is understood he was found to have met with the member of a gang, broken a curfew and failed a breath test.
Dappy's video also takes aim at X Factor's Simon Cowell and some of the show's stars.
It features people in Cowell masks and at one point, Dappy raps: "Where are they all now? They're bankrupt. Joe McElderry oh a stand-up, Alexandra (Burke) pull your socks up."
Dappy tweeted fans telling them: "Hope ur enjoying Tarzan Part 2. Like i told u im just warming up. Its only right 1 of us tells it how it should."
The lead singer of N-Dubz, which also includes his cousin Tulisa and friend Fazer, has previously courted controversy.
In 2010, his management company was forced to apologise after he sent threats to a single mother who had texted into a radio show calling him "vile".
Later that year picture of him taking the then-legal drug Mephedrone appeared in the newspapers prompting another apology.
Earlier this year he was charged with affray after an alleged fight at a petrol station in Guildford, Surrey.