WASHINGTON — A call from the Hay-Adams Hotel this past spring reporting that a Secret Service agent was trying to force his way into a woman’s room set in motion an internal investigation that has sent tremors through an agency still trying to restore its elite reputation.

The incident came a year after the agency was roiled by a prostitution scandal in Cartagena, Colombia, prompting vows from senior officials to curb a male-dominated culture of hard partying and other excesses.

The service named its first female director, Julia Pierson, seven months ago, and a broad inspector general report on the agency’s culture launched in the wake of Cartagena is expected to be released in coming weeks.

The disruption at the Hay-Adams in May involved Ignacio Zamora Jr., a senior supervisor who oversaw about two dozen agents in the Secret Service’s most elite assignment — the president’s security detail. Zamora was allegedly discovered attempting to reenter a woman’s room after accidentally leaving a bullet from his service weapon. The incident has not been previously reported.

In a follow-up investigation, agency officials also found that Zamora and another supervisor, Timothy Barraclough, had sent sexually suggestive emails to a female subordinate, according to those with knowledge of the case. Officials have removed Zamora from his position and have moved Barraclough off the detail to a separate part of the division, people familiar with the case said.

Details about the Hay-Adams episode and related findings were provided by four people who have been briefed on the case, including two who have viewed summaries of the internal Secret Service review.

Secret Service spokesman Ed Donovan declined to comment on the internal review of the Hay-Adams incident or the supervisors’ alleged behavior. He said that no employees — including Zamora and Barraclough — wished to comment.

An attorney for Zamora and Barraclough also declined to comment on the allegations or the Secret Service’s internal inquiry. Messages left for Zamora on his home phone were not returned; efforts to reach Barraclough through home and fax numbers were unsuccessful. A lawyer for the female agent in the protective division declined to comment. “We have always maintained that the Secret Service has a professional and dedicated workforce,” Donovan said in a statement, referring to the Hay-Adams incident. “Periodically we have isolated incidents of misconduct, just like every organization does.”

Donovan added that “we work diligently with our Office of Professional Responsibility and Department of Homeland Security Office of Inspector General” to resolve such cases “appropriately and quickly.”

But the inspector general’s office was unaware of the hotel incident or the related findings until The Washington Post began making inquiries.