The 37-year-old actor was recently interviewed for Marc Maron's WTF podcast, and although he opened up about the alleged abuse he endured at the hands of his father and in Hollywood as a child star, Culkin refused to divulge any information about his goddaughter.
'I am close with Paris,' he responded abruptly when asked about the friendship.
'I’m going to warn you now I am very protective of her so just look out,' he added. 'I am a very open book when it comes to things but like with her, she is beloved by me.'
Maron clarified that he wasn't dishing for 'dirt' on the daughter of the late Michael Jackson, to which Culkin replied: 'I’m just letting you know if we want to start going down that road it’s going to be a dead-end, you know, but I mean that in the fact that I love her so much.'
When the host further asked how the 19-year-old model was doing, he replied, 'She’s tall, and beautiful and smart. It’s great.'
The 37-year-old actor was incredibly close to music icon Michael Jackson and has remained close to the singer's three children since his sudden death in 2009.
Jackson and Culkin regularly document their friedship on social media, posting videos and images of everything from Paris lounging on her godgather's lap to the pair giving each other pedicures.
The two even share a matching tattoo.