(CNN) -- A man accused of kidnapping his daughter was taken into custody by the FBI on Saturday, and his daughter is with authorities, an FBI agent said.
Police in Boston, Massachusetts, say accused kidnapper Clark Rockefeller had several aliases.
An anonymous tip led authorities to an apartment in Baltimore, Maryland, where Clark Rockefeller was staying with his 7-year-old daughter, Reigh Storrow Boss, said Edward Davis, the Boston, Massachusetts, police commissioner.
The apartment, in Baltimore's Mount Vernon section, was near a marina where Rockefeller's 26-foot catamaran was docked, Davis said.
Investigators tricked Rockefeller into leaving his apartment by calling him to tell him that his boat was taking on water. As soon as he left the building, FBI agents arrested him and found Reigh in the apartment, Davis said at a news conference in Boston. Watch Davis describe the arrest »
Reigh "appears to be unharmed" and was "excited" to see the law enforcement officials, Davis said. Her mother, Sandra Boss, is en route to Baltimore to pick her up.
Rockefeller, 48, allegedly abducted the girl during a supervised visit last Sunday.
A social worker overseeing the visit told police that Rockefeller was carrying his blond-haired, blue-eyed daughter as they walked down a street in Boston, Massachusetts, when a black SUV pulled up next to them.
Rockefeller jumped into the vehicle, and it sped away with the girl inside, too, said the social worker, who was dragged a short distance as he tried to hold on to the SUV. He was treated for minor injuries.
Rockefeller faces charges of felony custodial kidnapping, assault and battery, and assault and battery with a dangerous weapon. Authorities said they would seek to extradite him to Boston this week.
Since the girl's disappearance, authorities had tried to track Rockefeller's movements. At first, they believed he was heading to a yacht or other boat on Long Island, New York, based on information from a woman described as a "personal relation" of Rockefeller's.
Boston police also acknowledged a reported sighting of the two in the Caribbean.
The girl's mother released a YouTube video earlier this week in which she pleaded with her ex-husband to return their daughter.
The couple divorced in 2007. Boss lives in London, England, where she is a partner with McKinsey & Co., a global management consulting company, the Times of London reported.
The paper reported that Boss was granted custody of her daughter and that supervision of Rockefeller's visits had been made mandatory because she was concerned Rockefeller would try to run away with the child.
Sunday was apparently Rockefeller's first supervised visit with his daughter.
Boston police said Rockefeller may not even be the suspect's real name. He has been known to use the aliases J.P. Clark Rockefeller, James Frederick, Clark Mill Rockefeller and Michael Brown, police said.
The London newspaper reported that Rockefeller told Boss he was a member of the wealthy Rockefeller oil family, descended from industrialist John D. Rockefeller and his only brother, William, who co-founded the dynasty. But the Rockefeller family issued a statement Tuesday denying any connection.
CNN's Laura Batchelor, Amy Sahba, Dan Lothian and Katherine Mackey contributed to this report.