Jean Brochu said in a report released Wednesday that the Brazilians' missteps make it difficult to conclude with absolute certainty what happened when Gatti died in 2009.
Brochu concluded that Gatti died a "violent death," but not at someone else's hands. The probable cause of death was listed as asphyxiation by neck constriction.
"Much of the debate surrounding the circumstances of the death revolved around the question of whether a third party was involved in Arturo Gatti's death," Brochu wrote.
"The conclusion of the Montreal pathologists to the effect that there is no clear evidence of foul play in Mr. Gatti's death means I cannot dismiss the formal conclusions reached by the authorities of the country where it occurred."
An investigation by Brazilian authorities had ruled the death a suicide. A private investigation ordered by one of his handlers concluded that Gatti's death was a homicide.
Brochu's report says Brazilian authorities mishandled forensic evidence, making it difficult to conclude with certainty what happened.
The coroner wrote that the Brazilian police investigation "does not meet the standards we have grown accustomed to here."
He said his analysis of Gatti's wounds, his blood and the events on the night leading up to his death produced no "clear and hard evidence" that a third party was involved in the boxer's death.
That means the Brazilian authorities' ultimate conclusion that Gatti committed suicide remains plausible.
Brochu also cast doubt about the results of an investigation done by private investigators in the U.S., at the behest of Gatti's former manager, Pat Lynch.
The popular junior welterweight champion retired in 2007 with a career record of 40-9, with 31 wins by knockout. He was found dead in July 2009 at an apartment he and his family had rented in the seaside resort of Porto de Galihnas.
The Gatti's family and his friends have steadfastly rejected the suicide conclusion. The family also has become engaged in legal disputes in Canada and the U.S. with Gatti's widow, Amanda Rodrigues, over his inheritance.
Rodrigues originally was arrested in connection with Gatti's death, but was released after an investigation determined suicide was the cause of death.
Rodrigues' lawyer said Wednesday that she hopes the report puts an end to the speculation about her client's involvement in the death.
"She's very pleased with the coroner's report. She's not surprised at all," Pierre-Hugues Fortin said during a phone interview.
"She always maintained that she was not involved in her husband's death, she claimed (this) in essence from the beginning, so in this respect she's very pleased."
Copyright 2011 by The Associated Press
