Five holiday home owners have been issued with warnings or "official advice" for digging into sea defences protecting thousands of properties.

The future of the shingle bank between Hunstanton and Wolferton is under review, after tests showed it was moving inland.

The Environment Agency (EA) is waiting for an engineer's report to see whether so-called trigger points have been reached, meaning the policy of maintaining the bank may no longer be viable and will need to be replaced with "managed realignment".

Eastern Daily Press: Property owners have been warned not to dig into the bank or place structures on itProperty owners have been warned not to dig into the bank or place structures on it (Image: Chris Bishop)

In February, property owners were warned by the EA not to dig into the bank or place steps or decking on it, because of fears this would weaken the defences.

Now the EA has confirmed that a number warnings have been issued. In response to a request under Freedom of Information (FOI) laws, it said: "Two people have received official warnings and three people have received official advice and guidance for breaches of legislation relating to the shingle ridge.

"There is not a standard warning letter, each warning letter is based upon a template but is tailored to each individual and case.

Eastern Daily Press: Steps which have been built up the shingle bank at HeachamSteps which have been built up the shingle bank at Heacham (Image: Chris Bishop)

"There are currently no pending prosecutions for breaches of legislation relating to the shingle ridge."

Warning letters are understood to request the removal of structures, adding if property owners do not comply the work may be carried out by the EA, which would charge them for it.

Those owning properties near the defences require the EA's permission to carry out any work within 16m of the bank.

Eastern Daily Press: Some of the thousands of properties protected by the shingle ridge, whose future management is under reviewSome of the thousands of properties protected by the shingle ridge, whose future management is under review (Image: Chris Bishop)

The report into the future of the defences has not yet been made public, with multiple sources saying it is now expected to be out in late May or early June.

But an EA newsletter has already warned that future work on the defences may be "undeliverable".