has revealed that his father was gay and he discovered that years after his parents separated when he was a toddler.
's father was an abstract expressionist painter who died in 1993, reported People magazine.
De Niro, 70, honoured his father in the HBO documentary Remembering the Artist: Robert De Niro Sr, premiering on June 9.
"He never told me. He was very private about it. He was loving and affectionate. But he wasn't the kind of dad who played baseball. He liked to take me to the movies on 42nd Street: King Kong, Beauty and the Beast," De Niro said.
As the Silver Linings Playbook star looked back on his five decades of acting and his own life as a father, De Niro said he knows the importance of passing along memories.
"I want my children to see what their grandfather did and how he lived. It was for the family," he added.