Brazilian police now say former world boxing champion and former Montreal resident Arturo Gatti committed suicide, and his wife has been released from jail in line with their finding.

Lead investigator Paulo Alberes told The Associated Press on Thursday that an investigation into Gatti's death has concluded that he killed himself.

The 37-year-old former champion boxer was found dead on July 11, in the apartment he was renting with his wife, Amanda Rodrigues, in the seaside resort of Porto de Galinhas in northeast Brazil.

The two had arrived there a few days earlier on a second honeymoon, along with their 10-month old son.

Authorities had originally detained Rodrigues, 23, on suspicion that she strangled her husband with a purse strap while he slept. But later, Brazilian authorities said a coroner's report led them to believe Gatti's death was self-induced.

Rodrigues said in a phone interview as she walked out of jail on Thursday that she believes Gatti may have killed himself because he was afraid she was going leave him, after they had a violent disagreement in public the night before his death.

"We had an argument in the street. Then he pushed me and I hurt myself. I believe that when we got home and he saw that he hurt me, he thought I would leave him, that I would tell him to just let me go, that I would separate from him," Rodrigues said.

"He did that in a moment of weakness," she added. "He was drunk, maybe he didn't know what he was doing, maybe he thought I would leave him the next day."

Earlier on Thursday, a state court judge in Brazil ordered that Rodrigues be immediately released.

"The detention of the suspect was no longer needed," the judge wrote in a ruling, because the investigation "excludes the possibility of murder," referring to the conclusion of the police investigation.

Gatti's family is reportedly considering hiring a pathologist, however, to perform a second autopsy on his body.

Meanwhile, friends of Gatti's in Montreal reacted with disbelief to the suggestion that the retired boxer had ended his own life.

"Anybody that knows Arturo Gatti, that knows him well, they know that this guy would never do something like that," Howard Grant, a boxing coach and friend of Gatti's, told CTV Montreal.

Gatti was born in Italy but learned to box in Montreal, where he was raised. During his 16-year career, he won the WBC junior welterweight title in 1995 and the WBC super-lightweight title in 2004. He retired three years later with a record of 40-9.

Montreal boxing promoter Yvon Michel called him "the most successful boxer ever from Quebec."

His funeral, which took place in Montreal on July 20, attracted some 1,000 people. Former heavyweight champion Mike Tyson paid his respects by sending a letter recalling the first time he met Gatti, when the boxer was only nine years old.

Gatti and his wife reportedly had a tumultuous relationship. Their son is currently in the care of Rodrigues family in Brazil.

With files from The Associated Press