Three boys who were left in intensive care after swallowing an "unknown substance" are believed to have taken ecstasy, the BBC understands.
They were found in an area near to The Bowl at the National Sports Centre in Douglas at about 14:30 BST on Thursday.
The boys, aged 11 and 12, have since been discharged from hospital. Tests are being carried out on the substance.
Police are investigating who the "controlled drugs" belonged to after the boys found them in Douglas.
Insp Gavin Callow said: "The boys became ill quickly and that it could have been a tragic situation."