
Police commissioner Norton Luis said a shoe lace from Harris' shoe was found around his neck, leading officials to the hypothesis that he may have committed suicide.
However, Luiz noted that the body of Harris - who would have turned 37 on Sunday and is a former star of Washington State University - was taken to the state capital Goiania on Monday, for further tests.
"The player may have been poisoned, or may have been a victim of any other type of violence," he noted.
The police official added that after the tests the body will be handed over to the sportsman's family, to be returned to the United States. A representative of the US Embassy in Brazil is closely following the investigations.
Harris - who played for the club Universo, from Brasilia - was found within an army compound in the town of Formosa, in Goias, after the authorities received an anonymous message about the location of the body.
He had been missing for two weeks, when he left Brasilia with an intention to travel to Salvador de Bahia. He took the bus to Goiania, from where he was set to take a taxi to the historic north-eastern city.
The taxi driver said Harris disappeared suddenly on November 4, during a stop at a petrol station.
Alleged eye witnesses said they later saw the player roam aimlessly and beg money.
Before that, Harris had played only three games for Universo. The club's basketball coordinator Ricardo Oliveira said his conduct had struck team-mates and club authorities as "strange."
"We have hardly had time to talk to him, but we realised he was strange. He behaved in a bizarre way, and seemed to think that people were saying bad things about him," Oliveira said.
However, he stressed that the player's death was a "shock."
"No one was expecting that," he noted.
The wife of the dead basketball player, Lori Harris - who is eight months pregnant and is in the United States - said her husband talked to her on the eve of his trip. She said he had told her of his desire to leave Brazil, because he was convinced he was in danger.