Norfolk police confirmed it has deployed officers at three locations along Norfolk's east coast as part of an on-going operation.
A spokesman for the force said the National Crime Agency was taking the lead on the operation, but did not give any further details.
Police are currently at Hopton, Caister and Hembsy.
MORE: More than £50m worth of cocaine has been discovered washed up on beaches in Hopton and Caister
A lifeboat has also been launched from Gorleston, but a spokesman for the coastguard said he was unable to comment further.
More details to follow.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here