Secret Service Director Mark Sullivan has cooperated properly with congressional investigators looking into the prostitution scandal in Colombia last month before President Barack Obama's visit, influential House members said Wednesday.

Rep. Peter King, the chairman of the House Homeland Security Committee, said Sullivan provided answers to 50 questions from his panel about the controversy in Cartagena that embarrassed the nearly 150-year-old agency and raised concerns of a possible security breach.

"I got the answers back last night, and I would say the answers were very detailed," King said on CNN's "Starting Point with Soledad O'Brien."

In addition, King said, Sullivan notified the Homeland Security Department's inspector general when the scandal became public in mid-April, "which showed that he wanted a real investigation."

Also Wednesday, the House Oversight Committee's leading members said Sullivan provided a "detailed response" to their separate list of questions about the incident.

"Director Sullivan's cooperation with our oversight efforts underscores his commitment to understand the extent of the problem and ensure that this unacceptable conduct does not occur again," said a statement by the panel's chairman, Darrel Issa, R-California, and ranking Democrat, Elijah Cummings of Maryland.

Even Republican Sen. Chuck Grassley of Iowa, a frequent critic of government resistance to congressional oversight, praised Sullivan's response to his request for details of any possible involvement of White House advance team staff in the scandal.

Grassley is demanding that the White House turn over all details of an internal review that found no wrongdoing by advance staff members, and he renewed his call Wednesday after receiving Sullivan's response that the Secret Service inquiry didn't involve White House records.

"Since the Secret Service did not request the records of the White House personnel, an open and transparent response from the president's counsel is even more imperative," Grassley said in a statement. "Unfortunately, more than a week after my inquiry, I've yet to hear from anybody at the White House. I appreciate the Secret Service's transparency in response to Congress, even with sensitive information."

King said Tuesday night that Sullivan's answers to his committee's questions disclosed that three of the 12 Secret Service agents involved in the scandal had refused to cooperate with authorities and submit to a polygraph test.

The three agents were among the first forced out of the service when news of the scandal in Cartagena broke, King said. The nine remaining agents took polygraph tests, and although none of them failed, some responses led to the loss of several jobs, he added.

On Wednesday morning, King said that no security breach occurred from the Secret Service agents consorting with foreign prostitutes in their hotel rooms shortly before Obama's arrival in Cartagena for last month's Summit of the Americas.

"We know that it appears that no material was obtained by any of the prostitutes. Nothing is missing. All the BlackBerrys are accounted for. There was no president's schedule available," King said.

"It does not appear that any of the 12 women had any involvement other than prostitution," King added. "They were not working for any narco-terrorist organization, and I think in a way the Secret Service has ducked a bullet."

Still, King said, the incident "goes against all the principles of the Secret Service."

"Because it was disclosed and there was no long-term security matter here, it gives the Secret Service the opportunity to clear up what has happened, do all it can to make sure it never happens again or at least minimizes it to make it very, very difficult for it to ever happen again," he said.

While King did not provide CNN copies of the responses -- which he said are marked "law enforcement sensitive" -- he highlighted several details Tuesday night.

Among other things, one agent said in the polygraph test that he was "actively engaged" with one of the prostitutes when she wanted to get paid, King said. In response, the agent threw her out of his room.

The agent told U.S. officials he didn't realize the woman was a prostitute, and he has not been fired.

U.S. officials have interviewed 10 of the 12 women involved in the scandal, King noted. The Secret Service and Colombian authorities are trying to track down the remaining two.

King said there weren't many surprises in the responses to his questionnaire.

"Sullivan was giving us good information all along," he said.

The top legislators on the Senate Homeland Security and Governmental Affairs Committee said Tuesday that they've also sent a letter to Sullivan asking for information on the incident.

A total of nine agents have resigned or are in the process of being forced out, while three other Secret Service agents were cleared of serious misconduct.

A source familiar with the investigation told CNN on Wednesday that money changed hands between nine Secret Service members and nine prostitutes.