The AU launched the investigation was in May and it invited all staff members who had cases of complaint to come forward for a confidential interview.
The investigating committee found “almost unanimous confirmation” of sexual harassment in the evidence of the interviewees, an AU statement says.
The investigation found that those most vulnerable to such exploitation were “short-term staff, youth volunteers and interns”.
Those responsible “position themselves as ‘gate-keepers’ and ‘king-makers’”, it said.
These staff “are well-positioned to make believable promises to young women that they will be offered contracts”, it continues.
Reporting incidents of sexual harassment was often counterproductive as there was no process, interviewees said.
South Africa’s Mail & Guardian paper says the inquiry was established after it reported on a petition signed by 37 female members of AU staff complaining about sexual harassment at the commission.
The AU Commission, headquartered in the Ethiopian capital, Addis Ababa, said that given the findings and serious allegations it would establish “a comprehensive sexual harassment policy that protects the victims and takes the strongest punitive measures against any perpetrator”.