The nurse who died after a hoax call to a hospital treating the Duchess of Cambridge was found hanged, Sky sources say.
Jacintha Saldanha was discovered on Friday morning in her room at staff accommodation near the hospital in west London. An inquest is due to open on Thursday.
"If it adds anything to this very tragic story it indicates a very determined bid to kill herself, rather than what some people describe as a cry for help," said Sky's Martin Brunt.
"I also understand ... that a suicide note was left in which she, we believe, gave some explanation for the actions that she's thought to have taken."
The 46-year-old mother-of-two was found dead days after an Australian radio station duped staff at King Edward Vll Hospital into revealing details of the Duchess's condition. She was suffering from acute morning sickness.
Two presenters on Sydney's 2Day FM radio station called the hospital pretending to be the Queen and Prince Charles.
Ms Saldanha, who took the call, transferred it to the ward where the Duchess was being treated. A second nurse then divulged details of her condition.
The post-mortem to establish the cause of Ms Saldanha's death began on Tuesday and has concluded, but the result will not be officially announced until a hearing at Westminster Coroner's Court on Thursday morning.
The death is not being treated as suspicious and the inquest is expected to be opened and adjourned as inquiries are continuing.
Initial official statements suggested Ms Saldanha was alive but unconscious when she was discovered. However, it is now understood she was found dead.
Speaking at Prime Minister's Questions, David Cameron said: "She clearly loved her job, loved her work, cared deeply about the health of her patients, and what's happened is a complete tragedy. There are many lessons that need to be learned."
Southern Cross Austereo (SCA) is to start running adverts again on 2Day FM on Thursday. Until the end of the year all profits the station makes from advertising will be donated to a memorial fund established in aid of Ms Saldanha's family.
A minimum contribution of AUS\$500,000 (£326,000) will be made, the company said.
Earlier this week Ms Saldanha's husband and two children paid tribute to a "loving mother and loving wife".
It is understood the family are making arrangements to return her body to her native India. A private memorial service is expected to be held later this week.