Rio de Janeiro's Military Fire Department said that one of the helicopters crashed on Sunday into the parking lot of a car dealership, where several electric vehicles were parked, igniting a fire that was extinguished.
Officials said an investigation was underway to determine the cause of the collision.
Police said 32-year-old Tree was on the list of passengers handed to aviation authorities but the bodies had yet to be formally identified.
Recognisable by his signature bowl cut, Tree was known for his songs Life Goes On and When I'm Down.
He released his fourth studio album, Love You Madly, Hate You Badly in April.
Tree performed in Buenos Aires, Argentina on June 4, and published a video on his Instagram on Saturday of him playing soccer in a Brazilian neighbourhood.
YouTuber KSI paid an emotional tribute to "legend" Tree who collaborated with KSI on the song Voices and is known for the track Miss You.
Argentine streaming channel Blender said that content creator Gaspar Prim Díaz - also known as Gaspi - was in one of the helicopters.
Gaspi had more than 2.8 million followers on YouTube and was 23.
"Thanks for your art, your magic and your sensibility, every one of us will miss you," Blender said on its X account.
Fernandes de Freitas, a tyre repair worker, said he saw one of the helicopters in flames following the midair collision, and noticed that one of the passengers jumped out of the other aircraft, before it hit the ground.
"It was terrifying, absolutely horrifying," De Freitas said.
with PA
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