For more information on this story, check out CNN affiliate KIRO
Washington (CNN) -- The Secret Service continued to be rocked Thursday by allegations of its agents' transgressions, though one U.S. government official cautioned against assuming there are systemic problems or that they are not properly investigated.
The new claims include an account stemming from El Salvador described by CNN affiliate Seattle TV station KIRO as very similar to the Colombia prostitution scandal purportedly involving members of the Secret Service and other government agencies.
The U.S. government official acknowledged there had been missteps among Secret Service members, while adding that such problems are to be expected given the agency's 147-year history.
Amid calls by some Republicans for a broader congressional-led investigation, the official was also quick to defend the government's internal review process and the role of the Secret Service's Office of Professional Responsibility in dealing with that agency.
"We have had employees that have engaged in misconduct," the official said. "People make mistakes."
Reports of other incidents involving members of the agency, which is charged with protecting the president and other top officials, as well as investigating criminal activity, have been brought to Congress, a congressional source said Thursday.
That includes the incident in El Salvador, which the congressional source said the Secret Service has told Congress it is looking into as well.
The KIRO report cited an unnamed U.S. government contractor who worked extensively with the Secret Service advance team in San Salvador before President Barack Obama's trip there in March 2011.
The source said he was with about a dozen Secret Service agents and a few U.S. military specialists at a strip club in the city a few days before Obama arrived.
The men drank heavily at the club, and most of them paid extra for access to a VIP section where they were provided sexual favors in return for cash, the source told the station.
The station reported that the strip club's owner corroborated the allegations. The owner confirmed that a large number of agents, and some military escorts, "descended on his club" that week and were there at least three nights in a row, KIRO reported.
The owner said his club routinely takes care of high-ranking employees of the U.S. Embassy in San Salvador as well as visiting agents from the FBI and U.S. Drug Enforcement Administration, KIRO said. The owner said his reputation for "security" and "privacy" makes his strip club popular with "those who want to be discreet."
The government contractor source said he told the agents it was a "really bad idea" to take the strippers back to their hotel rooms, but several agents bragged that they "did this all the time" and "not to worry about it," KIRO reported.
KIRO investigative reporter Chris Halsne told the CBS show "This Morning" on Thursday that he considers his source very credible, and he later told CNN that he had checked billing records, receipts, credentials and other information to confirm the contractor was with the Secret Service in Central America at the time of the incident.
The source told him about the alleged scandal last year, while Halsne was in El Salvador on a different story. Halsne said he pressed for details at that time, but the man didn't want any information from him to be used then in a news story. After the allegations involving Secret Service agents in Colombia surfaced, Halsne again pressed his source, who this time assented to the use of his account in the KIRO report.
CNN cannot independently confirm the allegations.
Responding to the KIRO report, Secret Service spokesman Edwin Donovan said, "The recent investigation in Cartagena (Colombia) has generated several news stories that contain allegations by mostly unnamed sources. Any information brought to our attention that can be assessed as credible will be followed up on in an appropriate manner."
Defense Secretary Leon Panetta said Thursday that his department is not investigating any of its troops about the reported incident in El Salvador. But the State Department is questioning its El Salvador embassy staff about the allegations, spokeswoman Victoria Nuland said Thursday.
The Drug Enforcement Administration also is prepared to look into, "in an appropriate manner and immediately," allegations that it deems "credible" regarding its agents in El Salvador, agency spokesman Rusty Payne said. But he added that, while the DEA has seen news reports, "We are unaware of any allegations of misconduct."
Sen. Chuck Grassley -- the top Republican in his chamber's Judiciary Committee, which was briefed Wednesday by Homeland Security Secretary Janet Napolitano on the Colombia scandal -- said the KIRO report "only reaffirms the need for independent investigations by the (Homeland Security Department's independent) inspector general."
"There are rumors flying about various incidents over several years about the conduct of Secret Service personnel, as well as other law enforcement and military personnel in locations around the world," the Iowa Republican said. "The only way to put to rest the rumors of a much wider problem is for the allegations to receive transparent and independent reviews."
Another Republican on that committee, Sen. John Cornyn of Texas, called for Congress itself to investigate "as part of our oversight responsibilities."
But Sen. Chuck Schumer, a New York Democrat and Judiciary Committee member, disagreed and said Napolitano's investigation needs to come first.
"After that, Congress should look into it and see what went wrong and what could be changed," he said.
The Washington Post reported Thursday that an unnamed source said such behavior is part of the culture at the Secret Service and not a one-time occurrence.
The Secret Service said it has no comment on the Post story, but a Secret Service official, who was not authorized to comment on the continuing investigation, said, "It's difficult for the Secret Service to defend against this," referring to the Post's article.
"The reaction by our leadership speaks for itself," the official told CNN, referring to the Colombia incident. "Everyone was sent home. There's an investigation. We have taken action regarding the agents."
Spokesman Jay Carney said Thursday that the White House would not comment on unconfirmed reports about other incidents, saying questions should be directed to the Secret Service.
The alleged prostitution scandal in Colombia occurred before the president's trip this month to a pan-American summit in Cartagena. Secret Service and U.S. military members are said to have consorted with prostitutes.
Nine Secret Service members have resigned or are being forced out as a result of the scandal.
The military has launched its own investigation into 12 troops who were in Colombia in advance of Obama's visit. The U.S. Southern Command said Thursday that the latest soldier included in this inquiry had "duty at the White House Communications Agency," which is part of the military.
Fresh off a meeting with Secret Service Director Mark Sullivan, Rep. Sheila Jackson Lee told CNN's "OutFront" on Thursday that she's learned the agency -- besides setting up working groups focused on its culture and outreach efforts, including to women -- will institute several measures in light of the uproar.
These include having a "professional development or personnel officer (go) on every trip the agents take out of the country," barring agents from being "associated with any place of bad acts" such as strip clubs and mandating that "no foreign nationals will be allowed in" an agent's hotel room.
"If this is the culture, then they want to immediately put it to rest," the Texas Democrat said, explaining the Secret Service's rationale.
CNN's Brian Todd, Dan Lothian, Carol Cratty, Tom Cohen and Alan Silverleib contributed to this report.