Heroin kingpin suspect Isaac J. Tindle, described by federal prosecutors as the millionaire owner of a dozen properties, two Rolls Royces and three other expensive cars, remained in jail here yesterday, unable to make a reduced bond of $4 million.

U.S. District Court Judge Alexander Harvey II ordered Tindle's bond reduced from $20 million to $4 million, but acknowledged that the reduction may be moot in light of Tindle's contention that he is presently able to scrape up only $25,000 to $50,000.

Tindle's attorney, John Mercer, argued during a bail hearing before Harvey that the Internal Revenue Service has "taken everything of value" from Tindle and his wife. The IRS has a lien on Tindle's home in Clinton, as well as several other apartment and office buildings he owns to satisfy what it says Tindle owes it in unpaid taxes.

"They've taken everything," said Mercer, "even his wife's computer and his dogs."

Tindle, 41, a slender bespectacled man, was indicted last April along with 13 other persons on charges of operating a multimillion-dollar, Mafia-supplied heroin ring in the Washington area.

Prosecutors described Tindle as the principal organizer of the ring and said he and others attempted to launder huge sums of illicit revenues through a network of video game parlors in the Washington area. Tindle's trial is scheduled for Oct. 3.

Tindle turned himself in to authorities shortly after his indictment and was ordered held on $20 million bond in Baltimore.

In his unsuccessful attempt to win freedom today, Tindle contended that the fact that he turned himself in was strong evidence that he would show up for trial and not flee.

Assistant U.S. Attorney Ty Cobb countered, however, that Tindle has every reason to jump bail since he has been charged under the so-called "kingpin" narcotics law, which carries a possible life sentence without parole. Under the kingpin law, Tindle is accused of heading a "continuing criminal enterprise" involving at least five other persons.

If convicted, Tindle also would stand to lose the five cars and 12 properties he owns under a forfeiture provision of the law.

According to court papers, Tindle owns eight properties in the District of Columbia and four in Prince George's County, with a combined value of $2.2 million.

In court today, Cobb said Tindle and his wife spent more than $1.5 million since 1978 in "identifiable funds" but earned only a small fraction of that in "legitimate funds."

Cobb said that when Tindle recently purchased a 1983 Rolls Royce Corniche convertible with a list price of $160,000, he made a down payment of $90,000, using a $69,000 cashier's check and a $21,000 personal check.