Police say they have made three substantial seizures of heroin in the island in the last few weeks.
Three weeks ago in the west of the island, £50,000 worth of heroin was recovered.
Police said the drug had been sent to the island through the post.
One male was arrested and is on remand pending their next court appearance.
This week, two men from the North West of England were arrested in Douglas and heroin worth £1,000 was recovered.
And yesterday (Thursday), £30,000 worth of heroin was seized in the south of the island.
A man and a woman appeared in court today on drugs offences. The man was remanded in custody and the woman bailed.
Separately, a man was arrested at Douglas sorting office yesterday afternoon on suspicion on importing cannabis through the post.
A police spokesman said: ’I can confirm that police arrested a male in connection with the importation of cannabis to the island via the post.
’Police will continue to work with other agencies to try to interrupt any means of importation of drugs to the island.’