A 12-year-old boy has collapsed and fallen seriously ill in unexplained circumstances.
Police officers were called to the boy's house in the early hours of Friday morning after he collapsed.
He was taken to hospital in a serious condition, where he remains.
The incident is being investigated by police, who still do not know what had caused the child to become ill.
They are appealing for witnesses who could help explain the circumstances which had led to his collapse.
A spokesman for Sussex Police said: "Police are investigating after a boy fell seriously ill in Crawley, West Sussex, in the early hours of Friday morning.
"Officers attended Byrd Road shortly before 00.30am after concerns were raised for the welfare of a 12-year-old boy who had collapsed.
"The boy was taken to hospital in a serious condition. He remains there in a stable condition.
"Inquiries are ongoing to establish the full circumstances of what happened and to identify if any offences have been committed.
"Police are currently awaiting the results of tests to determine what may have caused the boy to collapse."
Anyone with any information is asked to contact police online or by calling 101.
