WASHINGTON — A Democratic congressman asked the FBI today to drop its investigation of Roger Clemens because the pitching great had suffered enough from the probe into steroid use.

A candidate for New York mayor in 2009, Rep. Anthony Weiner said the FBI is too busy with more important crimes to spend time trying to determine if the ex-Yankees pitcher lied to Congress about taking performance-enhancing substances.

“Roger Clemens has been shamed. I think the public record is replete with examples of how he did not likely tell the truth. What is the public benefit of continuing with an FBI investigation?” Mr. Weiner said.

Mr. Weiner also suggested his fellow lawmakers had gone far enough with inquiries into steroids use by professional athletes and should let professional sports league handle the matter.

“The real incentive to clean up this mess is not a governmental one,” said Mr. Weiner, a Mets fan whose district includes parts of Queens and Brooklyn.

The FBI took over Mr. Clemens’s case after Congress asked the Justice Department to look into Mr. Clemens’s testimony at a February 5 deposition and a February 13 hearing. Mr. Weiner is not a member of the House Oversight and Government Reform Committee, which heard from Mr. Clemens.

Mr. Clemens testified he never used steroids or human growth hormone; his former trainer testified he injected Mr. Clemens with such substances at least 16 times between 1998 and 2001.

If investigators conclude Mr. Clemens lied on critical details, he could face charges of perjury, making false statements, or obstruction of justice.

In a letter to Attorney General Mukasey, Mr. Weiner wrote: “Whether or not Roger Clemens may have committed perjury should not compete with real national security threats for the FBI’s time, attention and resources.”

There was no immediate comment from the Justice Department today.