Nicki Minaj has cancelled her headline appearance at the BET Experience festival.

The music star was offended by a post on Twitter, which has since been deleted by the entertainment channel BET during the Grammy Awards on Sunday night (February 10).

The tweet which caused offence said that Minaj was "being dragged by her lacefront" after rival Cardi B won the prize for best rap album.

Tweeting after the wig-based quip, Minaj said: "Young Money will no longer be apart of the BET Experience or award show. Summer Tour dates dropping soon".

Now, the company have issued an apology and insisted that the post "should never have been written".

In a statement, BET Networks insist that they have supported Minaj "from the very beginning, adding: "Unfortunately, the respect we have for Nicki was violated by this post that should never have been written.

"The post does not reflect how we feel about Nicki. And further does not reflect our company values.

"We deeply apologise for the hurt, disappointment and confusion that this post has caused. We are committed to doing everything we can to address the situation."

BET added it is "conducting an internal audit" over the incident, and said it has apologised privately to both the rapper and her team, while the post has been deleted.

The network added: "We understand Nicki's position and look forward to continuing our dialogue with her."Finally, we apologise to all her fans. This should have never happened."

Before the apology, Nicki shared a lot of messages from fans slamming BET for its joke, and even encouraged one follower to ask for a refund for the festival in June.

She added: "I can't thank you guys enough for all the love & support you continue to show me. To everyone who said something sweet, thank you.

"Whether I read it or not, I felt it. From the bottom of my heart. I love you so much. So so so soooo much. Stay tuned (sic)"