US rapper ASAP rocky poses before the Christian Dior 2017 spring/summer Haute Couture collection in Paris.

Kim Kardashian West has reached out to President Donald Trump's son-in-law Jared Kushner on behalf of the rapper ASAP Rocky, who has been detained in a Swedish jail since last month, US media said Thursday.

Kardashian West contacted the White House out of concern for ASAP Rocky, who is imprisoned in Stockholm over his alleged participation in a brawl, according to The Washington Post -- and Trump was reportedly sympathetic to his plight.

After the reality star -- who is married to rapper Kanye West -- reached out to Kushner, the top White House adviser informed his father-in-law Trump, who "told Kushner he believed ASAP was being held unfairly, and wanted to help," entertainment outlet TMZ said.

A Swedish court on July 5 opted to keep ASAP Rocky, whose real name is RaKim Mayers, in custody on suspicion of assault while the fight is under investigation, over concerns that he is a flight risk.

Swedish authorities are expected to announce on Friday whether they will charge the rapper with assault or appeal to keep him in custody pending further investigation.

Kim Kardashian and Jared Kushner listen as US President Donald Trump speaks during an event.

A US State Department spokesperson told AFP the agency is "following this case closely" but did not comment further citing privacy concerns.

The 30-year-old rapper was arrested following a June 30 incident that was partially caught on video and published on TMZ.

ASAP Rocky, who was in Stockholm for a concert, can be seen throwing a young man into the street, then aiming several punches at him while he is still down.

On July 2, the rapper posted his own videos on Instagram, which he said showed the lead-up to the clash.

In those, the man can be seen arguing with the musician over a pair of headphones, and the artist repeatedly asks that the man and his friend stop following them.

More than 600,000 people have signed the petition #JusticeForRocky demanding the rapper's release, with celebrities including Cardi B, Diddy, Justin Bieber and 2 Chainz publicly supporting his plight.

"no more Sweden for me, ever," pledged rapper Tyler, the Creator over the situation.

Agence France-Presse