"What I can tell you right now is the tremendous regret that they have over their involvement in this situation," attorney Gloria Schmidt said in an interview Monday with ABC News Chief Anchor George Stephanopoulos on "Good Morning America."
Smollett, who is black and gay, told police he was attacked by two masked men near his apartment in Chicago around 2 a.m. on Jan. 29.
The two men, Smollett initially said, shouted racist and homophobic slurs at him as a rope was wrapped around his neck and an unknown chemical was poured on him. The alleged assailants, police were told, yelled "MAGA country," an apparent reference to President Donald Trump's "Make American Great Again" slogan.
Police identified and questioned two "persons of interest" captured on surveillance video near the scene around the time of the alleged attack. Those men, Abimbola and Olabinjo Osundairo, were arrested Feb. 13, but police didn't charge them and said at the time neither remained a suspect.
While being questioned by investigators, the brothers claimed Smollett paid them $3,500 to help orchestrate and stage the crime after he became upset that a letter threatening him, sent Jan. 22 to the Fox studio where the television series "Empire" is filmed, did not get enough attention, law enforcement sources told ABC News.
The memo line on the $3,500 check read that it was for personal training, sources said.
The brothers' attorney said the check from Smollett was payment for both the personal training and their help in staging the attack.
"They were training together and so they were paid for that, but they were also asked to do this favor for him," Schmidt said in the "GMA" interview Monday morning.
Schmidt said her clients "trusted" Smollett to have their best interests at heart, but the actor "really just took advantage of them."
"They worked with Jessie, they've known him, they were friends with him. This was someone who the brothers thought could help their career. Obviously Mr. Smollett has connections," she added. "This later turned out to be a big betrayal."
When asked whether her clients have evidence to back up their claims, Schmidt responded, "Of course."
On Feb. 20, Smollett was charged with felony disorderly conduct for filing a false crime report. By that evening, police officially had classified the actor as a suspect in the ongoing investigation. Detectives subsequently presented evidence to a Cook County grand jury.
Smollett, who has consistently denied any role in staging the alleged crime, turned himself in to police the next morning.
"Why would anyone, especially an African-American man, use the symbolism of a noose to make false accusations?" Chicago Police Superintendent Eddie Johnson, visibly angry, said at a Feb. 21 press conference. "How could someone look at the hatred and suffering associated with that symbol and see an opportunity to manipulate that symbol to further his own public profile?"
A judge set bond at $100,000 and ordered Smollett to surrender his passport. The actor, who pleaded not guilty, was released after posting 10 percent of his bail.
Last week, the Osundairo brothers testified before a grand jury, which ultimately returned a 16-count indictment against Smollett for disorderly conduct for filing a false police report, according to the Cook County State Attorney's Office. Schmidt said her clients "were not looking for anything" in return.
"They are working very hard right now to piece their lives together. I mean, this was life-altering," she said in the "GMA" interview Monday morning. "They know that this has impacted a lot of minority populations, so they are working very hard to move this in a positive direction."
Smollett is scheduled to appear in court Thursday.
ABC News' Monica Escobedo, Andy Fies, Kaitlyn Folmer, Chris Francescani and Stephanie Wash contributed to this report.