Sad News: Paul Reubens’ Cause of Death Confirmed 1 Month After Actor Dies at 70

Paul Reubens’ cause of death has been revealed a little over a month after the actor died at age 70.

Reubens’ immediate cause of death was listed as acute hypoxic respiratory failure, according to his death certificate, which was obtained by PEOPLE. The condition occurs “when your lungs cannot release enough oxygen into your blood,” per Healthline.

The late actor also had two forms of cancer at the time of his death. The primary type, which was listed as a sequential underlying cause, was determined to be acute myelogenous leukemia.

Acute myelogenous leukemia is “a cancer of the blood and bone marrow,” according to the Mayo Clinic.

Reubens had also been diagnosed with metastatic lung cancer — a cancer which “spreads to the other lung or spreads to other parts of your body,” per WebMD — in the months before his death.

The Blast was first to report the news.

Rubens, who was best known for playing his beloved character Pee-wee Herman, died on July 30 at the age of 70 after keeping his cancer diagnosis private for years.

“Last night we said farewell to Paul Reubens, an iconic American actor, comedian, writer and producer whose beloved character Pee-wee Herman delighted generations of children and adults with his positivity, whimsy and belief in the importance of kindness,” his rep told PEOPLE in a statement at the time.

“Paul bravely and privately fought cancer for years with his trademark tenacity and wit,” the statement continued. “A gifted and prolific talent, he will forever live in the comedy pantheon and in our hearts as a treasured friend and man of remarkable character and generosity of spirit.”

Reubens also apologized to his fans for not going public with the diagnosis in a poignant statement issued after he died.

“Please accept my apology for not going public with what I’ve been facing the last six years,” wrote the comedian. “I have always felt a huge amount of love and respect from my friends, fans and supporters. I have loved you all so much and enjoyed making art for you.”

Reubens debuted Pee-wee Herman at The Groundlings Theatre in 1981 before landing a spot on HBO’s broadcast and went on to play the character on the big screen in 1985’s Pee-wee’s Big Adventure and the 1988 sequel Big Top Pee-wee.

On the small screen, Pee-wee’s Playhouse ran on CBS for five seasons from 1986 to 1990. The show went on to earn 22 Emmy Awards, and Reubens was personally nominated for 14 nominations, winning twice.

Outside of his work as Pee-wee Herman, he played several other prominent roles, including the original film version of Buffy the Vampire Slayer in 1992 as well as TV appearances on 30 Rock, The Blacklist, Gotham and What We Do in the Shadows.

Never miss a story — sign up for PEOPLE’s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Reuben was not without his controversies. He was arrested in 1991 in Sarasota, Florida, for indecent exposure. He had specifically been caught masturbating while watching a film at an adult movie theater, but he pleaded no contest to the crime and avoided receiving a charge on his record. He was still required to complete 75 hours of community service.

Nearly a decade later, Reubens was arrested again in 2002 after child pornography material was found within his home (he said the images were part of a vintage erotica collection). He turned himself in to the Los Angeles Police Department and was charged with a misdemeanor for the possession. The charges were dropped in 2004 after he pleaded guilty to a lesser misdemeanor obscenity charge.