RIO DE JANEIRO -- Boxer Arturo Gatti's death was ruled a suicide by police Thursday and his wife, once suspected of killing the former champion, was released from jail.

Lead investigator Paulo Alberes told The Associated Press authorities decided Gatti killed himself on July 11 while at a seaside resort in northeastern Brazil.

When asked if police had determined the case was a suicide, Alberes said "yes." He offered no other details, though a judge -- in ordering the release of Gatti's wife -- cited the police investigation and wrote that "the victim took his own life, committing suicide by hanging."

The boxer's widow, 23-year-old Amanda Rodrigues, said in a phone interview as she walked out of jail she thinks Gatti may have killed himself because he was afraid she was going to leave him after the pair had a violent disagreement in public the night before his death.

The death of Arturo Gatti, left, seen fighting Thomas Damgaard in 2006, has been ruled a suicide by Brazilian officials. Ed Mulholland/WireImage

"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. He was drunk, maybe he didn't know what he was doing, maybe he thought I would leave him the next day."

A day after the 37-year-old Gatti was found dead, police said that Rodrigues had strangled him with her purse strap as he drunkenly slept.

But police began to back off the accusation about a week later after a coroner's report said Gatti may have killed himself as he was found "suspended and hanged." The autopsy report didn't exclude the possibility he was slain, but said he also could have died in an unexplained accident, or could have committed suicide.

"The police investigation concluded that Arturo killed himself," said Celio Avelino, Rodrigues' attorney. "I've said before it would have been impossible for her to suspend and hang a man of that size."

Judge Ildete Verissimo de Lima ordered the immediate release of Rodrigues after receiving the police report. The judge wrote that police informed the court "the detention of the suspect was no longer needed" as the investigation "excludes the possibility of murder."

Rodrigues said her priority was to see the 10-month-old son she had with Gatti, grieve for her husband and clear her name in the case -- though some of Gatti's friends said they still suspect her.

"All of my plans and dreams involved Arturo. I haven't been able to think of anything beyond that," she said. "My plan now is to stay with my son, my father, mom and sister, nothing more than this."

Gatti's body was discovered in the apartment he was renting with Rodrigues in the resort town of Porto de Galinhas. The pair had arrived there a few days before for a second honeymoon. The couple brought their son, who was unhurt and is in the care of Rodrigues' family in Brazil.

From the accounts of Gatti's family and friends, the two-year marriage with Rodrigues was tumultuous.

"She was yelling all the time, they were always fighting and she'd say 'I'm going to kill you!' when they fought," Gatti's mother, Ida, said in a telephone interview from Montreal shortly after her son's death.

According to records at the Court of Quebec's criminal and penal division, Gatti was charged on April 16 for violating a restraining order that had been filed against him. The records didn't indicate who filed the restraining order, but Gatti's mother confirmed that it was Rodrigues who had taken one out against him. She offered no other details.

Rodrigues stressed her innocence and defended her relationship with Gatti.

"There is no one who can doubt my love for Arturo or his for me. Arturo got married at 34 years of age, he was never married before, and this demonstrates the love that he had for me," Rodrigues said. "I was the only wife of Arturo and I want my good name back. Not only just for me, but out of respect for my husband and my son."

Gatti, who captured two world titles in his 16-year pro career, retired in 2007 with a record of 40-9.

Gatti's family and friends expressed disbelief that the boxer could have killed himself. "It doesn't make any sense," said Howard Grant, a friend and fellow boxer in adopted hometown of Montreal.

Before a memorial Mass in northern New Jersey, where Gatti honed his craft, his brother said the family may try to have Arturo's body exhumed and have an autopsy conducted in Canada. Joseph Gatti, of Wyckoff, N.J., said Arturo's relatives are deeply disappointed with Brazilian authorities.