Simon Monjack reportedly had two secret children at the time of his death.
The British screenwriter - who was found dead last month just five months after his wife Brittany Murphy died - is said to have hidden the existence of the children from two previous relationships and allegedly owed both child support.
According to website TMZ, Simon's family - including his brother, mother and therapist - discovered e-mails requesting money on his laptop after staying with Brittany's mother Sharon last week.
The documents on the computer claim he had a son from one woman and a daughter from another.
Evidence of money transfers were also found, showing Simon sent $48000 to his lawyer and other amounts overseas.
Simon's family passed the computer on to investigators, while Brittany's mother has filed a theft report with police after the laptop went missing.
Simon had claimed they were ready to try for a family before she died. - Bang