GREEN groups have praised police for warning airlines they were "unwittingly" aiding gangsters by exporting illegally caught shellfish.

At least one major international carrier has been asked by detectives to stop shipping razor clams to China.

Officers fear many of the clams - better known as "spoots" in Scots - are being harvested using banned electro-fishing.

Independent MSP and Green candidate John Finnie stressed police were right to try and cut off criminals from their markets.

He said: "Police are to be commended for their actions.

"They are trying to close down the market for the proceeds of a crime.

"I hope that the carriers will heed their warnings."

Many industry insiders say that the sheer volume of clams leaving Scotland could only have been harvested by organised crime groups flouting the ban.

However, other sources in the seafood industry insist that exported razor clams are harvested legitimately - without illegal electro-fishing.

The technique, which sees electrodes trailed behind boats, stun razor clams in the seabed causing them to rise up where they are easily collected by divers. It has been banned across Europe since 1998.

Legitimate businesses continue to lobby for a change in EU rules to enable them to resume electro-fishing.

Some firms say they are able to gather enough spoots to fill the holds of aircraft without deploying illegal methods and dispute police claims that electro-fishing is more lucrative than drug-dealing.

They reject calls for airlines to close down the trade, saying they could account for their shellfish. They did not, however, speak on the record.

Detective Chief Inspector Garry Mitchell said: "Illegal razor clam fishing is an emerging and developing crime type.

"It affects multinational companies who are unwittingly facilitating organised crime.

"There is no market for razor clams in Scotland. The market is in the Far East and they have to get there quickly so they don't spoil."

Police insiders believe there would be no illegal clam-fishing if there was no airline willing to carry the product to markets in China, especially through Hong Kong.

Alex Kinninmonth, head of marine policy at the RSPB, questioned whether large volumes of quality export product could be reached without electro-fishing.

He said: "You can get a huge volume of clams with electro-fishing with very little effort.

"As far as I know you could only get that kind of quantity using dredgers. And that is a disturbing method on the sea bed. But that is a bad method because you get broken shells and a poor product that is not very marketable to the Chinese.

"The electro-fishing limits the damage to the clam."

"But we don't know what the effect of electro-fishing is on the environment.

"It is illegal, it is unregulated and it is uncontrolled.

"The Scottish Government can't police the seas all the time.

"A regulated fishery could overcome the issues but you would need to know the answers to a lot of questions."

Legitimate fishing firms argue that, if properly controlled, they could shock clams.

The Scottish Government is considering making a bid to the EU to lift the ban in Scotland.

The Herald understands scores of crates of the clams - still alive in their shells - are every day being flown to China where they sell for £10 a kilo.

The clams are carried in the holds of commercial passenger airliners along with other lucrative Scottish seafood, such as crabs, being rushed to Far East markets.

Two divers have died while electro-fishing - and there are particular concerns that criminal fishing gangs may take safety shortcuts.