Singer Nancy insists she always knew she was not related to Ronan by blood and laughed off rumours suggesting the newsman was her half-brother, but she tells CBS Sunday Morning that the story hurt other members of her family.

The These Boots Were Made For Walking singer has now spoken out about the drama, calling out Mia for not doing more to end chatter about her son's dad.

Ronan Farrow has long been considered Mia and Frank's lovechild, and when the actress was asked if there is any truth to the rumour in a 2013 Vanity Fair article, she said, "Possibly".

Nancy Sinatra says, "I was kind of cranky with Mia for even saying, 'Possibly'... I was cranky with her for saying that. She knew better, you know, she really did. But she was making a joke! And it was taken very seriously and was just silly, stupid.

"He (Frank Sinatra) would just laugh it off... (but) we didn't laugh it off because it was affecting my kids, you know? They were being questioned about it and we all knew it was nonsense."