The Get Him to the Greek star was being interviewed for U.S. TV show Access Hollywood on Tuesday (26Jun12) when he suddenly picked up a phone belonging to producer Mark Noble and dialled the pre-programmed number for Noble's father.
He then engaged in a bizarre conversation as the laughing crew looked on.
Brand told Noble, Sr., ""I'm on Mark's show with Mark. I just wanted to say that Mark is doing a wonderful job here. You've raised a fine - if a little overly erotic - son. He's meeting very nice people at work... You've raised a fine young man, sir.""
Brand then asked to speak to Noble's mother but was told she was asleep, prompting the Brit to end the conversation, jokingly adding, ""Goodbye dad. I love you.""