The criminal godfathers, who control a multi-billion-dollar empire on such diversified interests as oil and heroin, household accessories and prostitution, have cast their evil eye upon a new source of wealth: the U.S. Treasury.

Apparently, the godfathers have reasoned that their skill at seducing politicians could be used to tap the greatest money well of them all: the tax coffers. justice Department sources report that the crime lords are secretly studying ways and means of getting a hold on the federal purse-strings.

They do not have in mind anything so gross, our sources say, as an underworld raid on Ft. Knox or an overt attempt to siphon money into the underworld. Their approach will be more sophisticated, involving secret intrigues, political alliances and financial manipulations.

The designs upon the Treasury will be accompanied, our sources predict, by a public-relations campaign to portray the Mafia as no more than a Sicilian brotherhood that exists largely in the minds of writers who have romanticized it beyond all reality. The mere mention of the Mafia will be protested as an insult to all Americans of Italian descent.

Federal investigators insist, nevertheless, that the Mafia dominates organized crime, that its roots go back to Sicily, that the godfathers are as shadowy and sinister as depicted in the movies, that their power is growing and that law-enforcement agencies seem unable to cope with them.

Italian-Americans shouldn't take offense, since they are also the most effective fighters against organized crime. And, of course, the underworld organization embraces all ethnic groups.

The first Mafia Pioneers made their way to the United States as early as the 1890s. They earned comfortable livings by blackmail, extortion, murder, dock racketeering and other sinister skills acquired in the old country.

In the 1920s, the Mafia went through an era of expansion in this country thanks to Benito Mussolini. The Italian dictator, not wishing to share the tribute extracted from the populace, lowered the boom upon the secret underworld organization. Suspects by the hundreds were rounded up, chained together and hauled into court to face trials that were more concerned with convictions than the niceties of justice. The heat was on.

All told, more than 2,000 members of the Mafia were thrown into Italian prisons without any democratic discussion about their civil liberties. Cannier members got the message and quickly caught the first available transportation to America.

The Mafia, it developed, flourished better in a democracy. The 18th Amendment had closed the nation's saloons and had opened up a multi-billion-dollar bootlegging industry. This suited the peculiar talents of the Mafia's oppressed refugees, who were pouring into the land of opportunity.

By 1925, rum-running had become the crime syndicate's primary source of profit. So lucrative a business cried for proper management, organization and systemization. Eventually, the advantages of better business methods brought the various mobs - Italian;, Irish and Jewish - together in a criminal combine to relieve the seemingly unslakeable thirst of the American public. The organization soon became dominated by the crafty and clannish Sicilians.

Only the foolhardy ignored the new order. There were a few, attracted by the high returns, who tried to slice their way into the racket without being invited. They attempted to steal customers, hijack illicit cargo and even expropriate breweries. The new order met the unwelcome competition with old-fashioned methods - machine guns, cement barrels and knives in backs. This activity was handled by a branch of the business that came to be known as Murder, Inc.

Bootlegging provided a financial base for the Cosa Nostra, the more intimate term that Mafia members use to refer to their secret society. From this base, the criminal brotherhood expanded its operations, reorganized its internal structure and formalized its objectives.

Areas of influence were carved out; specific territories were handed to those strong enough to hold them; the lower-rung members were granted a system of rough, bizarre justice; slush funds were created to overcome political obstacles; and an educational fund was established to send promising, young members to college so the outfit could gain some class.

This new look was brought about, it has been said, by such rising racketeers as Lucky Luciano and Frankie Costello. They belonged to a dapper, new breed of gangster who sought to bring polish and efficiency to the chaotic underworld. To this end, they called a national crime conference in Atlantic City in 1929, and their reforms were largely adopted.

Now the rising Mafia generation is even better educated and more sophisticated. The immigrants who had fled Italy a few jumps ahead of Mussolini made it a cardinal doctrine of the Cosa Nostra to keep clear of Washington. They feared the federal powers that Mussolini had used against them. But the new generation, wiser in the ways of the political processes in this country, has no such hang-up.

This could be ominous for the United States.