YOUNG children found dead at their Little Lever home alongside their mother had drunk massive amounts of methadone, an inquest has heard.

At Bolton Coroner's Court assistant coroner assistant coroner Peter Sigee was told that 27-year-old Tiffany Stevens had become convinced that she had brought her daughters, Casey-Lea Taylor, aged three and 18-month-old Darcey Stevens, into a corrupt world.

"I have chosen to kiill us in my children's best interests," she wrote in notes discovered after their bodies were found on January 21, 2019 at their terraced home in Arthur Street.

The inquest heard that relatives became concerned that they had been unable to contact her for a week and so entered the house through a back door.

In a statement, paramedic Kirsty Ogden told how she found Ms Stevens and Casey-Lea lying on a matress on the living room floor underneath a duvet. Both were dead.

And Darcey was found in a buggy by the front door. She was also dead.

Home office pathologist Prof Philip Lumb told the court that family had probably been dead for about a week.

Toxicology tests showed that Darcey died from an amount of methadone enough to prove fatal to an adult.

When Casey-Lea was examined she had also been given methaone and had been injected in her abdomen with insulin. Tramadol, and morphine were also found and Prof Lumb concluded she died from drug toxicity.

Ms Stevens had a fatal level of morphine in her system, had injected insulin and methadone, Tramadol and Pregabalin were found. None of the drugs had been prescribed to her.

In response to a question from Ms Stevens' mother, Bobby-Jo Stevens, Prof Lumb stated that the drugs Ms Stevens and the girls had taken would have rendered them unconscious before death.

"I don't think there would be any pain or suffering," he said.

The inquest continues.