''When the mobsters discovered there were millions in illegal profits to be made, they simply muscled in on the bootleggers,'' said Edward A. McDonald, the head of the Justice Department's Organized Crime Strike Force in the Eastern District of New York State. ''And the bootleggers, who are making millions, won't complain to us because that would kill the goose that lays the golden egg.''

Federal taxes on gasoline are redistributed to the states primarily for the construction and maintenance of interstate highways. New York State and local governments spent almost $3 billion last year for the design, construction and maintenance of highways with the Federal Government contributing about $550 million.

At the 1987 meeting in a Uniondale, L.I., hotel room Mr. Moskowitz unwittingly revealed to investigators that each bootlegger was compelled to operate ''under the umbrella'' or ''protection'' of one of the five Mafia families that are based in the New York region.

Shortly after the meeting Mr. Moskowitz, who operated two gasoline companies in Brooklyn, was found strangled to death in a wooded area in North Brunswick, N.J. Law-enforcement authorities say the 57-year-old man was probably killed to prevent him from cooperating in their investigation. Details of Problems

Last year investigations in the New York region by the Organized Crime Strike Force led to the convictions of five men on Federal charges of gasoline-tax evasion and money laundering. The trials provided these key details about the scope of the problem:

* A previously convicted Long Island bootlegger, Lawrence S. Iorizzo, testified that from 1980 through 1984 he funneled $360 million in stolen taxes to the Colombo crime family.

* Witnesses testified that in a six-month period in 1982 Vincent Aspromonti, whom prosecutors described as an ''enforcer'' in the Colombo crime family, laundered or concealed $11.5 million in stolen taxes through a branch of the Extebank in Hauppauge, L.I. A former Extebank vice president, George Ruggiero, who is a cousin of Mr. Aspromonti, was convicted of secretly transferring the money to other accounts.

* An undercover I.R.S. agent said that Mr. Moskowitz and another gasoline dealer in Brooklyn, Shae Presaizen paid him $37,500 in bribes to obtain Federal licenses that would aid tax-evasion schemes.