A form of nepotism prohibited within federal agencies has become “open and widely accepted” at the Energy Department, according to a federal watchdog report.

Energy Department inspector general Gregory H. Friedman said in the report last week that one of the agency’s senior managers advocated for three of his college-age children to be hired for department internships last year.

The unnamed manager, who served in an executive role with the agency’s energy efficiency and renewable energy division, contacted 12 officials to inquire about opportunities for his children, according to the inspector general.

Investigators found that one department reversed its previously announced decision to not hire interns for 2012, after the senior official contacted division leaders.

All of the official’s children were hired by the agency during that year, according to the report. Two of the officials who made those hires told investigators they did not feel pressured by the father, the report said.

Nonetheless, the inspector general was critical of the manager advocating on behalf of his children. “Nepotism, or even its appearance, can have a decidedly negative impact on morale within an organization,” he said in the report. “The impact is likely severe, especially when considering the intense competition for . . . intern positions within the department.”

Federal law prohibits public officials from appointing, employing or even advocating for their children or relatives to be hired within their agencies.

Nonetheless, investigators found the issue of nepotism to be widespread within the Energy Department, suggesting that DOE officials were largely unaware of the rules.

“Despite the department’s ethics program and information regarding prohibited personnel practices, advocating for the selection of relatives appears to have become an open and widely accepted departmental practice,” the report said.

The senior manager told investigators that he did not believe he had done anything wrong and that a human-resources official from his division had told him no conflict would exist as long as the children did not work under their father’s direct supervision.

The report noted that the Pathways Program, established by the Office of Personnel Management at the urging of President Obama, was already helping address the issue of nepotism by requiring all applicants to apply to open job announcements in order to be eligible for consideration.

The Energy Department has promised to determine what circumstances led to the hiring of officials’ relatives and take steps to ensure such actions will not happen again, according to the report.

“The Energy Department is committed to fair, open and transparent hiring processes that ensure every candidate is evaluated equally,” said agency spokesman Bill Gibbons. “As recommended by the inspector general, the offices of the general counsel and the chief human capital officer are reviewing the information in the report as well as the circumstances surrounding these intern hires. The department will take appropriate action based on those findings.”

The agency has broadcast a message to all employees explaining the rules for preventing nepotism and promised to place additional emphasis on such matters during its annual ethics training, the report said.