A spokesperson for the Civil Police Department of Rio de Janeiro told NBC News its consumer delegations department is probing the alleged "crime of endangering the life and health" of concertgoers at Nilton Santos Olympic Stadium last Friday.
The massive concert venue, one of the first stops on the international leg of Swift's record-breaking Eras Tour, was packed with thousands of fans despite the scorching temperatures. That included Ana Clara Benevides Machado, who fell unconscious during the Grammy winner's second song.
Machado died at a hospital later the same night. While her cause of death has not yet been revealed, Rio's Municipal Health Department said she suffered cardiorespiratory arrest.
At the time of the show, temperatures in Rio hovered around 40C paired with 70 per cent humidity, which made it feel closer to 60C.
Some concertgoers reportedly fainted while others complained of oppressive heat in the stadium as well as limited access to water.
Video circulating on social media in wake of the show also appeared to show Swift gasping for air after performing her hit Bejeweled. She postponed her concert the following night as a result of the sky-high temperatures, writing on social media that "the safety and well-being of my fans, fellow performers, and crew has to and always will come first."
The singer also mourned Machado's death in an Instagram story, telling fans she was "overwhelmed by grief".
On Thursday, Time4Fun CEO Serafim Abreu posted a video apology to those who "did not have the best possible experience."
"We know the enormous responsibility we have to organise an event of this scale, which is why we did not economise in our efforts or resources to follow the best global practices in our industry to guarantee the comfort and safety of all," Abreu said.
