She declined to give further details, saying it was unclear what had happened since Dirie vanished early Wednesday. Belgian media reports said police found her Friday afternoon walking the Brussels' Grand Place square.
Hours earlier, police had announced they were launching a nationwide search for the former model, who had last been seen getting into a cab after a mix-up over a hotel.
Dirie gained international fame as a model posing in Chanel ads and acting in the 1987 James Bond movie "The Living Daylights" before launching her campaign against female genital mutilation ini 1996.
She shocked the world with a best-selling book "Desert Flower" that described how her genitals were sliced off with a dirty razor blade without anesthesia, and then stitched together.
Now a U.N. goodwill ambassador, she was due to speak on genital mutilation in Brussels at two conferences on women's rights organized by the European Union, including one on Thursday attended by Secretary of State Condoleezza Rice.
News of Dirie's disappearance came a week after French police said they had found the body of another former model of African origin who had campaigned against female genital mutilation. Guinean-born Katoucha Niane was discovered floating in the River Seine in Paris.
The French police said an autopsy showed no signs of foul play, raising the possibility that she may have fallen accidentally into the river. However, Katoucha's family members say they suspect homicide.
Dirie's manager, Walter Lutschinger, said she had been involved in an altercation in a hotel reception area after a taxi driver took her to the wrong branch of the Sofitel hotel chain. The police were called and drove Dirie around Brussels looking for the correct hotel because she had apparently forgotten where she was staying.
At one hotel, while staff and police were checking for her name on a computer, Meilleur said Dirie stepped out saying she planned to buy cigarettes from an all-night kiosk, but instead climbed into a taxi and drove away.
An Austrian citizen, Dirie was attacked in her Vienna apartment in 2004 by a Portuguese handyman who had stalked her. The man was given a five-month suspended sentence by an Austrian court.