Justin Bieber says Fox News host Laura Ingraham "should be fired" for appearing to laugh when she was discussing the memorial procession of rapper Nipsey Hussle.
He posted on Instagram saying: "How dare you laugh in the face of a person who has passed on."
Nipsey Hussle was shot dead outside his clothing shop in LA last month. He was 33.
Radio 1 Newsbeat has contacted Fox News for comment.
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Laura Ingraham absolutely disgusting what you did on national television. How dare you laugh in the face of a person who has passed on. Doesn’t matter who it is. But disrespecting someone’s who was a pillar in the community and did right by people? Did you not think about the family who just lost a love one and now have to see you mock him on national television It’s absurd and you should be fired period. #repost #spreadawareness
Nipsey Hussle's memorial procession happened on 12 April and Laura Ingraham spoke about it on her show the next day.
The conservative presenter mentioned the anti-Donald Trump song FDT, which Nipsey appears on along with rapper YG.
It was released in 2016, before Mr Trump became US president.
A clip of Laura Ingraham speaking about the song and laughing with contributor Raymond Arroyo was cut together in a post which went viral when it was shared by rapper The Game.
Justin Bieber posted: "Absolutely disgusting what you did on national television."
He added: "Doesn't matter who it is. But disrespecting someone's who was a pillar in the community and did right by people?
"Did you not think about the family who just lost a loved one and now have to see you mock him on national television".
He also called for Laura Ingraham to be sacked.
Laura Ingraham is known for being a strong supporter of Donald Trump.
She's caused controversy before - she denied being racist when she said "massive demographic changes" in the US were a "national emergency".
The host has also argued with basketball player LeBron James in the past when he criticised the president.
And she apologised to Florida school shooting survivor David Hogg after she mocked his university rejections on Twitter a month after the shooting.
Drake, Rihanna and J Cole are among those artists who have paid tribute to Nipsey Hussle, who died on 31 March.
Former US President Barack Obama also wrote a letter where he said the rapper's "choice to invest in [his] community... is a legacy worthy of celebration."
Real name Ermias Asghedom, the rapper was part of a gang in LA, before setting up a community centre in the Crenshaw neighbourhood.
One person was killed at his memorial procession as shots were fired into the crowd, while three others were injured.