Federal investigators are accusing a state assemblyman of lobbying his own colleagues in exchange for more than $500,000, raising concerns of a potentially wider corruption problem in Albany.

Assemblyman Anthony Seminerio of Queens is the eighth state lawmaker from New York City to be indicted or sentenced for abusing his office since 2003. That doesn’t include the state comptroller, Alan Hevesi, also of Queens, who resigned after pleading guilty to a felony.

Mr. Seminerio is the latest in a string of high-profile New York politicians — including Governor Spitzer and a Westchester County district attorney, Jeanine Pirro — to be embarrassed by being caught on a wiretap. Neither Mr. Spitzer nor Ms. Pirro was charged with any crime, though Mr. Spitzer resigned. The wiretaps in the Seminerio case include conversations with a slew of other New York politicians. Though their names were not released by prosecutors, their identities were the topic of intense speculation yesterday in city and state political circles.

Mr. Seminerio allegedly used his position to benefit his private clients, hiding their payoffs by setting up a consulting firm. The charges appear to be similar to the case that federal officials are trying to build against a former Senate majority leader, Joseph Bruno, whose consulting work while in office has been under investigation for the last two years.

The U.S. Attorney for the Southern District of New York, Michael J. Garcia, has made rooting out public corruption a priority of his office since assuming the role of top federal prosecutor in Manhattan. Mr. Garcia said that Mr. Seminerio’s arrest yesterday points to a loophole in the state’s disclosure laws. The veteran assemblyman apparently got the idea to start up his consulting business from two senators, according to prosecutors who recorded his conversations, but did not name the senators.

“Assemblyman Seminerio put his office up for sale to those willing to pay the right price,” Mr. Garcia said. “The absence of genuine transparency in Albany provides cover for officials seeking to enrich themselves at the public expense.”

Mr. Seminerio’s assembly office declined to comment, and neither he nor his attorney could be reached yesterday.

Mr. Seminerio, a Democrat who served as a corrections officer before joining the Assembly 30 years ago, allegedly connected his “consulting” clients with powerful government officials who could further their interests. The U.S. attorney’s office refused to identify the government contacts involved by name, instead describing them as various legislators, including committee chairs, and high-ranking agency officials. There is no indication in the complaint that they knew Mr. Seminerio was illegally profiting from their relationships with him.

Mr. Seminerio’s alleged clients — some of whom were undercover or secretly cooperating with prosecutors — included executives involved in health care, corrections, and real estate. For example, prosecutors said, he promised to advocate a hospital’s interests by speaking with an Assembly committee chair about the state’s health care budget.

“I could talk to anybody in Albany,” he said in an excerpt of the conversation, which was recorded by the FBI. “I’ll take care of you.”

In all, Mr. Seminerio received more than $500,000 in payments since 2000, according to prosecutors. Mr. Garcia said Mr. Seminerio was able to avoid disclosing the payments by funneling them through a consulting firm, “Marc Consultants.” Under state rules, legislators must list sources of income in excess of $1,000. Mr. Seminerio’s 2006 report to the Legislative Ethics Committee, which is available online, lists Marc Consultants as one of those sources without having to indicate where the money originally came from or disclosing publicly how much it was.

Mr. Seminerio’s practice may not be an isolated case, considering the investigation into Senator Bruno, who has denied any wrongdoing, and the suggestion that Mr. Seminerio was inspired by two other lawmakers. Those allegations, if proven valid, would represent a new twist on the old revolving door practice of lawmakers cashing in on their government contacts after they leave office. In Albany, if the prosecutors’ account is correct, at least some lawmakers may have beenfunctioning as paid lobbyists even before they left office.

Mr. Seminerio’s case illustrates that New York’s disclosure rules are “a laughingstock,” said a former executive director of the New York State Commission on Lobbying, David Grandeau.

The state’s legislative ethics rules, he said, “are more interested in enabling that behavior than they are in stopping it,” he said, referring to the corruption cases. “Once one legislator knows about a perk that’s available, that gets around pretty quick. Who you can go to to get the seats to the Yankees, who you can go to to get cheap car rentals, and who you can go to to set up your consulting practice. They share that information.”

Mr. Bruno’s office declined to comment.

Meetings that Mr. Seminerio allegedly set up involved a Health Department official who “just became the Director of State Operations” — presumably Dennis Whalen, who serves in the governor’s office.

In another excerpt provided by prosecutors, Mr. Seminerio spoke with a person identified as “a leader of the Assembly” — possibly Speaker Sheldon Silver — who assured him that hospital budgets would not be cut despite Governor Paterson’s release of what he called a hospital “hit list.” Mr. Seminerio then relayed the news to a hospital executive, according to the excerpts, noting that he had been “yelling and screaming” to the Assembly leader about the cuts.

Representatives for Mr. Whalen and Mr. Silver declined to comment when asked if they were the officials identified in the transcripts. In a statement, Mr. Silver noted the “very serious” charges against Mr. Seminerio and said he is cooperating with the U.S. attorney’s office.

The prosecutors’ excerpts also identified a chair of a New York State Assembly committee whom Mr. Seminerio lobbied. The chairman of the Assembly’s Committee on Health, Richard Gottfried, said yesterday that he was not involved.

“I had conversations with any number of my colleagues expressing concerns” about hospital cuts, he said. “I had no reason to think those conversations were motivated by anything other than concern for their local hospital.”

Mr. Gottfried said he did not know if Mr. Silver was one of the officials identified in the excerpts.

Mr. Seminerio, who serves in the 38th Assembly district and claims on his Web site to be tough on criminals, was released on $500,000 bail. He is facing a single count of defrauding the public of his honest services, which carries a maximum penalty of 20 years in prison.