Although Heath Ledger's family couldn't be at the Golden Globe Awards on Sunday, they were there in spirit as the actor was honored posthumously for his wicked portrayal of the Joker in The Dark Knight.

"We are overjoyed for him," his father Kim Ledger told PEOPLE of his son's win for best supporting actor in a drama, and added: "It's wonderful."

Ledger, of Perth, Western Australia, cited personal reasons for not making it to the ceremony held at the Beverly Hilton Hotel.

Dark Knight director Christopher Nolan accepted the award for the actor. "On behalf of all of us who worked with Heath on Dark Knight, I accept this with mix of sadness and incredible pride," said Nolan. "He will be eternally missed but he will never be forgotten."

Costar Aaron Eckhart says Heath's recognition is "bittersweet." "Just that we're talking about him, remembering him, we're showcasing his talent and him as a human being, is very important to me. For us – everyone in The Dark Knight – this is all for Heath," Eckhart told PEOPLE at the ceremony.

"I get the chills every so often talking about him," added Eckhart. "I knew Heath as an actor. I felt his spirit and I admired him."

Heath Ledger, 28, was found dead in a New York apartment nearly a year ago of an accidental overdose of prescription drugs.