The death of a non-binary student the day after a fight inside an Oklahoma school toilet has been ruled a suicide, the state medical examiner’s office has said.

A summary post-mortem examination report was released more than a month after the death of 16-year-old Nex Benedict, a student at Owasso High School.

Family members said Nex had been bullied at school and the teenager’s death in February drew concern from LGBT+ rights groups, as well as attention from Oklahoma’s governor and the White House.

“From the beginning of this investigation, Owasso police observed many indications that this death was the result of suicide,” Owasso Police Department Lieutenant Nick Boatman said in a statement.

“However, investigators did not wish to confirm that information without the final results being presented by the Oklahoma Medical Examiner’s Office.”

In an emergency call on February 8, Sue Benedict — Nex’s grandmother and legal guardian — had expressed concern about a head injury. The teenager was conscious and alert after a fight a day earlier when they told police about an attack by three girls that occurred after Nex squirted them with water, according to police video released last month.

The report shows Nex had toxic levels of two drugs in their system and died of an overdose. A complete post-mortem examination will be released in 10 days in accordance with state law, the medical examiner’s office said.

Mr Boatman would not confirm whether or not police found a note from Nex at the scene.

In video footage from the hospital on the day of the altercation, Nex explains to an officer that the girls had been picking on them and their friends because of the way they dressed. Nex claims that in the toilet, the students said “something like: why do they laugh like that”, referring to Nex and their friends.

“And so I went up there and I poured water on them, and then all three of them came at me,” Nex tells the officer from a hospital bed.

Paramedics responded to the family’s house and performed CPR on the teenager before rushing them to the hospital, where they later died.

Family members have said Nex was non-binary, which means they did not identify as strictly male or female.

“Bullying and harassment have a significant impact on students and, tragically, many of these youths believe that suicide is the only option for peace,” said Brandon Dilawari, a case manager at Rainbow Youth Project USA, a group that aims to improve the safety and wellness of LGBT+ young people.

“This is not an isolated incident by any means.”

The group reported a spike in calls from Oklahoma to its national crisis hotline after news of the teenager’s death became public.