Two people have been arrested on suspicion of murder after the death of a two-year-old boy from Doncaster.
Emergency services were called to a house on Bosworth Road at about 11am on Wednesday following reports the boy was in cardiac arrest, South Yorkshire Police said.
The child, from the Adwick area of the town, was taken to hospital where he died on Thursday afternoon.
A post-mortem is expected to take place later.
A 36-year-old man and a 32-year-old woman, both from Adwick, have been arrested.
The pair are in police custody where they will be questioned by officers.
Detective Chief Inspector James Axe said: "The loss of any life is tragic, and the death of this little boy is undeniably devastating.
"Our thoughts are with those who are affected and our specialist officers will continue to support them.
"We have a dedicated team of officers assigned to this investigation.
"Two people are in custody and we are working hard to establish the exact circumstances leading up to this child's death."
:: Anyone with information about the incident is asked to call police on 101 quoting incident number 293 of January 8 2020.