WATCH: HBO Documentary 'Remembering the Artist: Robert De Niro, Sr.' [VIDEO]: Robert De Niro Opens Up About Gay Artist Father

Premiering June 9 on HBO, a brand new documentary delves deep into the life of one of the biggest movie stars of all time: Robert De Niro. Though this special isn't exactly about the Raging Bull actor, rather the subject is his father, Robert De Niro, Sr., who was an artist, and gay.

Entitled Remembering The Artist: Robert De Niro Sr., the special's first trailer has the subject's son opening up about his father, who died about 20 years ago. In the clip, you learn that De Niro wants this documentary to serve as the acclaim his father's talents deserved. But the documentary also shows how De Niro viewed his father's sexuality.

Watch this trailer here:

In a new interview with OUT Magazine, De Niro opened up about his artist father. Here is an excerpt:

It's been more than 20 years since Robert De Niro Sr.'s death from cancer, but his memory is fresh for his son, who has preserved his father's final home and studio in New York City's SoHo. Filled with books, paintbrushes, and hundreds of canvases, some of which he never finished, it looks like pop stepped away for a coffee and should be back to finish another still life before dinner. The loft remains a quiet shrine to an artist that few recognize, perhaps mistaking his figurative paintings for a late Matisse or another French master. Now 70, the actor has decided to reveal this hidden sanctum and his own struggle with his late father's memory in a new documentary that premieres June 9 on HBO. In Remembering the Artist: Robert De Niro, Sr., the son tears up as he reads from his father's diaries. He shares intimate stories of his father's despair about his sexual orientation and his stagnant artistic reputation. At one point, as De Niro was ascending to Hollywood's top tier, he made a last-ditch effort to rescue his father, who was sick in Paris, where he'd been living as a starving artist. It's clear that De Niro regrets that he wasn't able to help him more before he died, and the film becomes a moving portrait of a son who wants to resurrect his father's legacy before it's too late. 

Read more HERE.