In December 1976, the Angolan government trading company, Importang, wanted 1,000 tons of palm oil. It contacted a Portuguese supplier, which in turn chose a Danish shipowner, Preben Maagefelt, to act a s a carrier.

On December 29, Massagefelt made out a bill of lading showing that the oil had been loaded in Copenhagen aboard a ship called the Cool Girl.

In fact, the oil was in Malaysia and the Cool Girl in dry dock in Rotterdam. But no one checked and, on presentation of the forged documents, the Union de Banques Suisses [Ubs] paid out $560,000 against an Angolan lettler of credit.

The Angolans, pleased with the facility of the transaction did another deal with the Portuguese firm, this time for 1,500 tons of beef worth $1.57 million. Again Maagefelt made out false bills of lading and again the UBS paid out.

Maagefelt used this share of this deal to pay for the palm oil, which eventually did reach Angola. But this two partners in Portugal siphoned off their million into banks in Copenhagen and London. The meat never arrived.

Then just two months later, UBS paid the same Portuguese company $6.8 million for 13,240 tons of shelled Mozambiquan peanuts for the Angolan oil extraction industry. When the cargo finally arrived, in September 1977, it turned out to be groundnut cake, the husk left after the oil has been extracted -- virtually worthless.

Infuriated by this and the other deceptions by then beginning to unravel, the Angolan authorities arrested the two Greek carriers, ships on timecharter to a Bermuda -- registered company run by a Brazilian national. For good measure, they arrested two other Greek ships that happened to be in Angolan waters at the time, also contracted to the Brazilian.

Maagefelt was arrested, convicted of fraud and sentenced to five years' imprisonment. "He was just in it to prop up his sagging business," says Eric Ellen, chief constable of the Port of London Authority Police and president of the International Association of Airport and Seaport Police [IAASP].

The people left holding the bag are Importang, who can ill afford such losses in precious foreign currency resources, and the unwitting Greeks whose ships lie rusting in Luanda.

The case highlights some of the elements in a wave of frauds that has hit international shipping during the past three years and which may have cost the industry up to 100 million pounds.

Since 1977, the London -- based Salvage Association has reported 83 vessels which have failed to deliver cargoes for reasons unconnected with normal marine perils. The incident has increased to such a degree recently that Chief Constable Ellen feels the frauds must be the work of organized gangs.

The Mafia may be involved according to Mike Harper, editor of The Shipbroker, the journal of the Institute of Chartered Shipbrokers.

Said Harper in a recent editorial: "The Mafia has moved from its bootlegging violence and gang warefare to more sophisticated crimes, and the relatively easy pickings which are available in the world of international freighting must be very attractive to them.

If Chief Constable Ellen has his suspicions, he meticulously points out that there is "no evidence" linking either the Mafia or the Chinese Triad gangs to the swindles.

What he does stress is that this is not just another elegant white -- collar crime. This is real on -- the -- waterfront stuff practiced by "voracious gangsters" and involving murder, arson and criminal damage.

The problem started with the shipping slump of 1976-77. Many marginal shipping businesses went bankrupt and shipowners were frequently faced with a cargo on board and no prospect of payment. They took to selling it in lieu, a legitimate thing to do.

Less scrupulous operators, however, nothing the possibilities, began to work out illegal variations on this theme. Favorite dodges have been:

To send half a consignment, collect full payment, then not send the rest.

To take payment for one grade of goods and then provide a consignment of inferior quality.

To hire a ship, paying on installments, draw full freight from the shipper, and then disappear owing the shipowner the majority of his fees.

To change the name of a ship while at sea and sell its cargo during an unscheduled stop.

To pretend to load a cargo but in fact take nothing on board, then scuttle the ship at sea and claim the insurance.

It is, however, becoming tougher to get away with such crimes.

At the urging of Chief Constable Ellen, wearing his IAASP hat, Interpol last November set up a section specifically to coordiante marine fraud investigations. And, in April this year, the London based International Chamber of Shipping announced that it was working on a new code of shipping practice.

Following a seminar in May, the Institute of Chartered Shipbrokers has invited representatives of 15 shipping-related organizations to form a commission to conduct a broadly based study of the problem.

Part of the problem is getting the parties to acknowledge there has been a fraud. Banks are said to be particularly unwilling to admit they have been duped. One London bank paid out half a million pounds on a fraudulent deal and did not contact police even after the affair had been exposed in the press.