Two people have been charged with causing or allowing the death of a two-year-old girl who ingested the heroin substitute methadone.
Barry Jones, 41, and Michelle King, 29, both of Jameson Street, Blackpool in Lancashire, have been charged in relation to the death of Sophie Jones.
Sophie died on Tuesday night after being taken to hospital.
Mr Jones and Ms King will appear in custody at Blackpool Magistrates' Court on Saturday.
They have been charged under the Domestic Violence Crime and Victims Act 2004, police said.
A post-mortem examination into Sophie's death at Blackpool Victoria Hospital proved inconclusive.
Police said toxicology tests later confirmed that she had ingested methadone.
Methadone is most commonly used in the UK in the treatment of opiate dependence, such as heroin.