SEATTLE – Half a century after a U.S. Senate committee identified him as an organized crime figure, Seattle’s 90-year-old strip club magnate and convicted racketeer is still at it, federal authorities say.

Agents on Monday raided four clubs owned by or affiliated with Frank Colacurcio Sr., and his son, Frank Jr., as well as their homes and offices, heralding what could be the final round in the family’s six-decade fight with the law. Documents filed in U.S. District Court said the Colacurcios have been underreporting attendance, cheating the city out of more than $3,000 a month in taxes, and skimming money their dancers earned performing illegal sex acts.

And as recently as last fall, Colacurcio Sr. continued to pay his own dancers as much as $1,000 for sex, an FBI agent wrote in an affidavit.

The clubs have not been shut down, and no current criminal charges have been brought against the Colacurcios. However, Seattle U.S. Attorney Jeff Sullivan said investigators have uncovered extensive evidence of racketeering, mail fraud and money laundering. Typically, such evidence is never made public prior to an indictment. But in this case, prosecutors on Monday obtained a temporary restraining order preventing the Colacurcios or their associates from selling or transferring three strip clubs – Rick’s in Seattle, Sugar’s in Shoreline, and Honey’s in Everett – or their hiring and bookkeeping offices.

Sullivan said he intends to use the federal Racketeer Influenced and Corrupt Organizations Act, commonly known as RICO, to have the properties forfeited to the federal government.

“For far too long, the Colacurcios’ organization has made big money operating their clubs as fronts for prostitution,” he said. “The Colacurcios have designed the clubs, the payment methods and the policies that encourage prostitution and to ensure they are the ones getting rich off these illegal sex acts.”

Lawyers for the Colacurcios did not return calls seeking comment. They have 10 days to ask for a hearing to challenge the restraining order. In the past, one lawyer, Gilbert Levy, has noted that the pair has never been charged with violent criminal acts.

That’s not to say they don’t have a past. Frank Sr., the son of a King County farmer, received his first conviction in the 1940s, for having sexual relations with a 16-year-old girl. He entered the topless nightclub business after making a name for himself in Seattle’s pinball industry in the 1950s.

In 1957, hearings before a U.S. Senate organized crime committee identified him as a racketeer. In 1971 he was convicted federally of running a bingo racket and sentenced to three years; in the mid-1970s he served more than two years on a tax evasion conviction that was eventually overturned on appeal. In 1981 he was convicted of tax fraud for skimming profits from a Bellevue club, and in 1991 he and Frank Jr. were convicted in a similar scheme, this time involving clubs they operated in Alaska.

This year, the Colacurcios pleaded guilty to felony criminal charges in Seattle’s 2003 “Strippergate” campaign-finance scandal. They each agreed to each pay $75,000 in criminal and civil penalties. The pair secretly funneled thousands of dollars in illegal campaign contributions through friends, relatives and business partners to the re-election campaigns of three Seattle City Council members, shortly before a vote on a rezone to allow for more parking at Rick’s.

It was that last incident that gave rise to the current investigation, which has included a Seattle police officer who infiltrated the organization as a club manager last summer; confidential informants; and undercover vice cops who posed as customers or secretly filmed acts of prostitution – though Sullivan was quick to note that none participated in prostitution.

A 99-page affidavit filed in support of the restraining order is chock full of incidents where dancers were observed performing sex acts or offering to do so, for prices ranging from $40 to $500. In some cases, the document said, undercover agents watched as the Colacurcios saw what was going on and did nothing to stop it, or in which they freely discussed prostitution at the clubs. Dancers told the agents that if they were arrested for prostitution at Rick’s, they were simply moved to another club until the charge was resolved.

Seattle Police Chief Gil Kerlikowske called it “the most significant organized crime investigation we have ever undertaken,” and added that the enterprise had “done considerable damage to this city.”

“It’s an organization that has made its money on the backs of women,” he said. “It’s about violence and organized crime. It’s not about the morals police.”

Six cold-case homicides were reopened as part of the investigation, he said, and three were solved – though none was tied to the Colacurcios.

Investigators estimate that the chronic underreporting of attendance at Rick’s cost the city of Seattle more than $3,000 per month in lost tax revenue. That was based on data from a surveillance camera installed outside the club in June 2006 to count customers entering the establishment.

In July 2006, while Rick’s reported 7,929 customers, the camera recorded nearly 14,000, the affidavit said.

The affidavit also said ATMs and credit card machines in the clubs dispensed tokens instead of cash that customers would use to pay dancers. But when dancers redeemed the tokens, they were given less cash than the tokens’ face value – evidence of skimming, the affidavit said.