One process server claimed to have made 13 round-trips in one day to serve legal papers between Brooklyn and upstate Cattaraugus County - a nearly 800-mile distance supposedly made more than a dozen times within 24 hours. That was one of the many egregious examples of fraud cited by state Attorney General Andrew Cuomo, who Tuesday announced the arrest of Long Islander William Singler, head of one of the largest process-serving firms in the state. Singler is charged with running a massive fraud scheme in which his employees claimed to serve legal papers that allegedly were never delivered. As a result of the actions by Singler, the head of American Legal Process in Lynbrook, and the process servers he employed, thousands from Long Island and around the state never had notice of pending legal actions against them by creditors, and never had a chance to contest them, Cuomo said. Consequently, many had their finances frozen or wages garnished, without being present for a court hearing, the attorney general said. "If proven true, the schemes detailed in the cases filed Tuesday undermined the legal rights of thousands of citizens by corrupting our legal system and abusing individuals who happened to have consumer debts," Cuomo said. The arrest of Singler was the first criminal case brought in a wide-ranging investigation by the attorney general's office into possible abuses by three different professional entities involved in debt collection, according to sources familiar with the scope of the probe. The three businesses are process servers, law firms that specialize in debt collection, and so-called debt advisory services, the sources said. Newsday first reported on the investigation earlier this week. Cuomo charged Singler with a scheme that involved thousands of instances of so-called "sewer service," in which the notice required to be given to the defendants in a suit is not properly served, but might as well have been dropped down a sewer. Cuomo's office also filed criminal charges and a civil suit against Singler's firm and filed a notice the attorney general intended to sue a Farmingdale law firm for allegedly violating the state consumer protection laws. The firm, Forster and Garbus, is a major one in the state that specializes in debt collection and employs Singler's firm in many of its debt-collection actions, Cuomo said. Singler's attorney, Corey Winograd of Manhattan, said his client was not guilty. "Mr. Singler vehemently denied the charges and never authorized or condoned, or organized any sewer service. . . . He placed his trust in process servers working for American Legal Process betrayed that trust." Cuomo said that of the 98,000 summonses that American Legal Process swore it had served between January 2007 and last October, 28,000 were done for Forster and Garbus. Ronald Forster, the senior partner of Forster and Garbus, said the firm intends to "vigorously defend" the lawsuit, adding, "it's kind of silly to hold me responsible" for the actions of an independent contractor. Singler was arraigned in District Court in Hempstead on fraud charges and was released without bail. If convicted on all charges, Singler could face up to 7 years in prison.