Fort Worth, Texas ? Fifty-one members of Congress have requested an investigation into the suspected forgery of memos used by CBS to report on President Bush’s service in the National Guard.

Kathy Colvin, a spokeswoman for the U.S. Attorney’s Office in Dallas, said Tuesday that officials were “still consulting” with the Justice Department in Washington on whether to launch an investigation.

The Texas Rangers, meanwhile, have also been asked to look into the matter by U.S. Rep. Lamar Smith of Texas, in a letter signed by him and other Republicans in Congress.

“A crime may have been committed to influence the outcome of a presidential election while our commander in chief leads the war on terror,” Smith wrote. “This is a grave offense that demands the attention of the appropriate law enforcement and investigative authorities.”

The four memos — now being sharply questioned — were purportedly written in the early 1970s by a commander in the Texas Air National Guard. They said that Bush, as a young member of the Guard, was not meeting expectations and that another commander wanted to “sugarcoat” it.

CBS used the documents for its Sept. 8 report on “60 Minutes” about Bush’s service in the Guard. The network has since apologized for the report and has begun an internal probe.