Two divers have been fined more than £60,000 after plundering shipwrecks off the Kent coast.

David Knight and Edward Huzzey, both from Sandgate, raided ships and illegally kept eight bronze cannons from the wreck of a 19th century British merchant ship in the English Channel.

Their haul was estimated to be worth more than a quarter of a million pounds targeting the shipwrecks of German submarines from the First World War and an unknown 200-year-old wreck carrying English East India Company cargo.

Now the pair have been fined £63,500. Knight must pay £7,000 and Huzzey £6,500 with both men ordered to pay £25,000 costs.

They also took three propellers from German submarines, lead and tin ingots as well as other artefacts.

The Maritime and Coastguard Agency said diary entries revealed Knight and Huzzey used explosives and sophisticated cutting equipment to free wreck material.

Knight, 51, a roofing contractor and marine businessman of Castle Road and Huzzey, 55, a seafood technician, of Granville Parade, admitted a total of 19 offences between them under the Merchant Shipping Act with the first theft believed to have taken place in 2001.

Under British law, finders of lost underwater treasures have a legal duty to inform the MCA and deliver the items to the authorities if requested.

The MCA first thought six of the missing cannon had been sold on but have retrieved them in the last fortnight.

Alison Kentuck, the MCA’s receiver of wreck, said: “It is not a case of ‘finders keepers’. Our message is clear: all wreck material found within or brought within UK territorial waters must be reported to the Receiver of Wreck.

“Finders of wreck have 28 days to declare their finds to the Receiver. This case demonstrates what could happen to you if you don’t. By reporting wreck material you are giving the rightful owner the opportunity to have their property returned and you may be adding important information to the historic record.

“Legitimate finders are likely to be entitled to a salvage award, but those who don't declare items are breaking the law and could find themselves, just like with this case, facing hefty fines."

"The sentence today sets an important precedent in the fight against uncontrolled salvage by a small criminal minority who have no appreciation for our national maritime heritage." Mark Harrison, English Heritage

Passing sentence at Southampton Magistrates Court today, District Judge Calloway, said: "The scale of the operation has to be considered to have been on an industrial scale: the resources employed were valuable and substantial, using good quality lifting equipment and explosives.

Mark Harrison, English Heritage's national policing and crime adviser, said: "The sentence today sets an important precedent in the fight against uncontrolled salvage by a small criminal minority who have no appreciation for our national maritime heritage.

"Huzzey and Knight are friends and clearly operated in close co-operation to actively scavenge for material from the wrecks they explored."

Mark Dunkley, English Heritage's maritime archaeologist said: "English Heritage takes very seriously all cases of heritage crime which robs us of our shared history.

"However, we recognise that the majority of divers do act responsibly and comply with the laws and regulations relating to historic wreck sites and salvage."