CHICAGO (AFP) - Was the incident actually a hoax? An investigation into an alleged attack on an openly gay black actor has "shifted" and police are now seeking a follow-up interview with the Empire cast member, a spokesman said.

Jussie Smollett, 36, reported to the police on Jan 29 that two men had yelled racial and homophobic slurs, poured bleach on him and tied a rope around his neck while he walked downtown in Chicago.

The change in direction came two days after the police said the two "potential suspects" had been released without charge and as media outlets reported that the incident could have been staged.

"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 spokesman Anthony Guglielmi said.

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

Multiple media outlets reported that the two men are brothers who were arrested at Chicago's O'Hare airport upon their return from a trip to Nigeria.

At least one of the men reportedly worked on Empire, a TV series about the fortunes of a hip-hop mogul and his family battling over control of a multi-million-dollar music company.

In an emotional interview with ABC's Good Morning America, Smollett gave details of the purported attack and said he was angry at doubts about its veracity.

Initial reports of the attack shocked the entertainment industry and brought waves of support from advocacy groups and politicians.