The incident occurred at Cornish beauty spot Crackington Haven, where beach pebble theft has led to the parish council installing warning signs informing beachgoers that the practice is unlawful.

Under the Coastal Protection Act 1949 it is illegal to remove stones from public beaches and St Gennys Parish Council has warned visitors who do so face fines of up to £1,000.

Parish clerk Barry Jordan told The Telegraph: “Those who saw the damage of the floods a few years ago know what water can do, take away the pebbles and the haven would be damaged during every storm.”