Jean-Claude "Baby Doc" Duvalier, the former Haitian dictator who is back after 25 years in exile, was on Tuesday charged with stealing millions of pounds in public money while in power.
Mr Duvalier, 59, was accused of corruption, embezzlement and other offences during his brutal 15-year rule, which ended when he fled to France amid an uprising in 1986.
It is alleged that he siphoned millions out of the poverty-stricken island over several years. Aristidas Auguste, Haiti's chief prosecutor, said: "His fate is now in the hands of the investigating judge".
The former president-for-life, who had been expected to give a press conference explaining his return, was instead apprehended at his luxury hotel by dozens of police officers, some wearing riot gear.
He was earlier holed up in his hotel being questioned in private by Mr Auguste and a judge, Gabriel Amboisse.
Mr Duvalier was taken to a court in Port-au-Prince, where he faced several hours of questioning behind closed doors. Hundreds of supporters cheered him as he was released on Tuesday night.
It was unclear how much Mr Duvalier was accused of stealing. In 2004, Transparency International estimated that he embezzled $300-$800m while in power.
In the early years of his exile many of his assets, including a yacht in Miami and four apartments in New York, were frozen by authorities around the world.
It was thought his fortune had since dwindled. But last year a Swiss court ruled reclaim at least $4.6m from previously frozen bank accounts in the country, due to the expiry of charges against him.
After he was released Mr Duvalier and his girlfriend, Veronique Roy, were driven back to their hotel in a 4 x 4 with a police escort. His lawyer said he had to remain "at the disposal" of state prosecutors.
Miss Roy denied that he had been arrested. A judge will now decide if there is enough evidence for a trial. His deliberations could take a maximum of three months.
Following his surprise return on Sunday night, Human rights groups had promptly called for Mr Duvalier to be prosecuted for alleged atrocities, including the murders of thousands of political opponents.
He assumed the presidency in 1971 at the age of 19, after the death of his father, the brutal Francois "Papa Doc" Duvalier, and continued ruling the poverty-stricken island through fear and corruption.
Both father and son used a thuggish secret police force, known as the Tonton Macoutes, to torture and kill up to 30,000 of the Haitians who opposed them.
Baby Doc's return came a year after the devastating earthquake that killed more than 300,000 Haitians and displaced a million more. The island's recovery has been blighted by delays and a cholera outbreak.
It also coincided with the first presidential elections since the disaster, which have produced disputed early results, prompting suspicion about Mr Duvalier's motives.
After landing, he said he was "well disposed and determined to participate in the rebirth of Haiti", but later insisted: "I'm not here for politics." The US government said yesterday that Mr Duvalier's return was a matter for Haitians, but made its first critical comment on the situation.
P.J. Crowley, a spokesman for the state department, said: "Having a former dictator return to Haiti just adds to Haiti's ongoing burden." Henry Robert Sterlin, a former ambassador under Mr Duvalier, now working as his spokesman, said on Tuesday: "Let's see if they dare put him in prison."