Police believe Jussie Smollett 'staged' racist attack - reports

There are growing doubts about the truth of a suspected violent hate crime against US actor Jussie Smollett.

The Empire star, who is openly gay, told Chicago authorities he was attacked on January 29 by two white men "yelling out racial and homophobic slurs".

The 36-year-old claimed an unknown chemical was poured on him and a rope was tied around his neck, and that the men yelled "This is MAGA country" as they fled the scene.

On Wednesday (local time), two Nigerian brothers - one of whom appeared as an extra on Empire - were arrested in relation to the alleged crime, casting doubt on Smollett's description of his attackers as white.

On Friday they were released without charges, with police citing "new evidence".

"We can confirm that the information received from the individuals questioned by police earlier in the Empire case has in fact shifted the trajectory of the investigation," Chicago Police spokesperson Anthony Guglielmi said.

"We've reached out to the Empire cast member's attorney to request a follow-up interview."

CNN reports anonymous law enforcement sources told them authorities now believe Smollett paid the brothers to stage the attack.

In an interview with Good Morning America, Smollett said he was sure the two figures seen in surveillance footage of an area near the alleged assault were his attackers.

Authorities confirmed the brothers were the two men from the footage, and it's since been revealed they know Smollett personally, with their lawyer claiming they have previously trained with the actor at the gym.

Records show the two men bought the rope found around Smollett's neck from a local Chicago hardware store, as well as two plain red hats they wore during the alleged assault, CNN reports.

Hundreds sprang to Smollett's defence in the wake of his original allegations, but now high-profile supporters have expressed their doubts on social media.

"His story has seemed suspect for days now but I genuinely thought no one, and especially no one that famous, could make something like that up," feminist author Roxane Gay said on Twitter.

Singer Clay Aiken also expressed scepticism about the alleged assault.

Smollett is standing by his account of what happened, with his representatives calling claims he orchestrated the attack "ridiculous".