NO official action will be taken over dredging around the Outer Harbour site, as enforcers say they learned of alleged activity too late to attempt to build a robust case.

Campaigner John Cooper fears more than 640,000 cubic metres has been dredged from the Outer Harbour by vessels without relevant licences - allegations Great Yarmouth Port Company (GYPC) strongly denies.

Unauthorised dredging can result in hefty fines, with a case in Falmouth, Cornwall seeing the owner of the town’s inner harbour slapped with a �630,000 bill in 2010.

And Gorleston man Mr Cooper says he has been in touch with the Marine Management Organisation (MMO) over alleged breaches since 2007.

MMO officers agreed that ship tracking systems “appear to indicate the movement of dredging vessels in and around the vicinity of Great Yarmouth Outer Harbour”.

The tracking data is taken from the vessels’ Automated Identification System (AIS). But marine officers noted there was not sufficient evidence to prove the type of work the dredgers undertook.

A letter from the MMO to Mr Cooper reads: “The majority of these AIS tracks relate to activity which occurred over two years ago which unfortunately presents us with a problem from an enforcement perspective. Had we received this information at the time we would have been better placed to deal with it more effectively.”

It goes on to state there are not sufficient grounds to proceed further “at this time”, but a spokesman told the Mercury the Outer Harbour is still being investigated.

“This case is still ongoing, and can therefore not be discussed in further detail at this point,” he said.

Eliza O’Toole, vice chairman for GYPC, stressed the company is always compliant while dredging works are carried out.

“It is not unusual for there to be dredgers working in and around ports,” she said. “We have a range of activities which occur in the harbour using dredging vessels from time to time and which are subject to different approval requirements depending on the activities and the type of dredger. On all occasions we are compliant with the relevant statutory requirements for the various activities and vessels including for the initial construction of, and ongoing works on the Outer Harbour.”