A lot has been written about Shah Rukh Khan having a surrogate child, but the Bollywood superstar refused to talk about it, saying it's a very personal matter, and he shall break his silence at the right time.

"This is not the right time to talk about it... we are going to get on the train baby and not talk about my baby. This is very private and personal," Shah Rukh told reporters here Wednesday on being asked about reports related to his surrogate child.

He was here to launch the music of his forthcoming big ticket release "Chennai Express".

"There is a mix of sadness and happiness about this news. Let the sad part get over... will talk about it later. I would request the people who are doing the interrogation to do a thorough check," Shah Rukh said.

Shah Rukh did not explain the "sad" part. However, it is being speculated that the baby in question is underweight. The surrogate baby was reportedly born May 27 at a hospital here.

The 47-year-old is married to Gauri Khan and together, they have two children - son Aryan and daughter Suhana.