Golovnina had reportedly gone to the toilet, and had not stepped out for a long time when people present there barged in, the sources told Dawn online.
She was reportedly lying on the floor covered in vomit.
The bureau chief was rushed to the Pakistan Institute of Medical Sciences (PIMS) where she was pronounced dead.
The hospital will carry out a post-mortem before handing over the body to Russian authorities.
The cause of Golovnina’s death could not be determined immediately and the authorities have launched an investigation to ascertain the facts of the case.