Lil Peep's death last month at 21 was the result of an accidental drug overdose on substances such as Fentanyl and Xanax.

The 21-year-old rapper, whose real name was Gustav Åhr, died November 15 on his tour bus in Tucson, Arizona due to 'combined toxic effects of fentanyl and alprazolam' - the latter a generic term for Xanax - according to a report from TMZ, citing the Pima County Medical Examiner.

The New York native also had recreational drugs including cocaine and marijuana - and prescription medications including Hydrocodone, Hydromorphone, Oxycodone, Oxymorphone and Tramadol - in his system at the time he died, the outlet reported, citing the medical examiner, adding that he did not test positive for alcohol at his time of death.

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Tragic turn: Lil Peep, pictured this past June in France, died last month as result of an overdose of Fentanyl and Xanax, medical officials said, according to TMZ

The combination of Fentanyl and Xanax was particularly lethal, as medical experts say blending the two can result in severe respiratory damage, with consequences including a coma or death.

The rap artist's brother Karl 'Oskar' Åher, 23, told People in the wake of his death that he was shocked by his sibling's passing, noting that Lil Peep 'was not struggling' amid the period when he died.

'It was an accident, it really was an accident: He was super happy with where he was in life,' Oskar said.

In January, Lil Peep - who was romantically-linked with actress Bella Thorne for a time - opened up to the outlet Pitchfork about his ongoing battle with depression.

Open book: The rapper was candid about his mental health, drug use and sexuality. He was pictured in France in June

On the mic: The rapper was snapped performing in Anaheim, California in September

'I suffer from depression and some days I wake up and I’m like, "F***, I wish I didn’t wake up,"' he said. 'I don’t express that side of myself on social media.

'That’s the side of myself that I express through music. That’s my channel for letting all that s*** out.'

Oskar told the publication that the Awful Things performer ingested a pill that could have been laced with a lethal substance, causing his premature passing.

Sad day: Fans congregated in Long Beach, New York on Sunday to pay tribute to the rapper

Mournful: The rap artist's name Gus, short for Gustav, was written in the sand over a heart on the gloomy day

Remembrance: Lil Peep's mother Liza Womack spoke to mourners at the assembly

'We have heard there was some sort of substance he did not expect to be involved in the substance he was taking,' Oskar said. 'He thought he could take what he did, but he had been given something and he didn’t realize what it was.'

The rapper, who rose to prominence on forums such as YouTube and Soundcloud, was honored by fans in Long Beach, New York last week at a memorial service.