Nottingham Crown Court has heard how a two-year-old boy died after drinking his mother's methadone from a 'sippy cup' beaker while she slept.
Sally Dent from Belper in Derbyshire woke up on March 13 last year to find her little boy Riley unconscious next to her in bed.
The BBC reports that the 32-year-old mum was a heroin addict who had left the methadone in 'easy reach' on a bedside table.
Both she and Riley's dad Shaun Binfield, 44, deny Riley's manslaughter and child cruelty charges.
Yvonne Coen QC, prosecuting, told the court that Sally Dent had a history of drug abuse, and was taking methadone to try and combat her addiction to heroin.
She said it was 'grave negligence' that the methadone had been left in a child beaker and in a place where Riley could easily each it.
"Not only would [the beaker] have attracted him to it like a little bee to a honeypot but it was also within easy reach of him," Ms Coen said.
The court heard that when paramedics arrived at the family home in Belper, Nottinghamshire, Riley was lifeless. He was transferred to hospital but pronounced dead shortly after.
Post-mortem results found the little boy had enough methadone in his blood, stomach and urine to kill him. It is thought he had ingested between 10 and 20ml of the substance.
His parents had originally told police officers that the toddler must have climbed on top of a wardrobe to reach the methadone, where it was usually stored in a locked box.