The States police made the seizure in St Clement on Saturday (11 December) and the male suspect remains in custody while an investigation continues.
Anyone who has any information about the alleged offence is asked to call officers on 612612 or contact Crimestoppers anonymously on 0800 555111.
Islanders who may be struggling with drug or alcohol misuse are advised by the force to get in touch with the Alcohol and Drugs Service on 445000 Monday to Friday.
