Mr Duvalier says he has returned to help the people

Mr Duvalier, 59, also known as "Baby Doc", arrived on a flight from France where he had been living in exile.

It was not clear what prompted his return, though he said he wanted "to help the people of Haiti" following last year's devastating earthquake.

He arrived amid political uncertainty after disputed presidential elections.

Prime Minister Jean-Max Bellerive said there was no reason to believe Mr Duvalier's return would destabilise the country.

"He is a Haitian and, as such, is free to return home," said Mr Bellerive.

Amnesty wants "justice"

Mr Duvalier's return has prompted rights group Amnesty International to urge the authorities in Haiti to bring the former president to justice.

The organisation says he should be tried for alleged human rights abuses committed during his regime.

"The widespread and systematic human rights violations committed in Haiti during Duvalier's rule amount to crimes against humanity. Haiti is under the obligation to prosecute him and anyone else responsible for such crimes," the organisation's special advisor Javier Zuniga said.

He called on the Haitian authorities to "break the cycle of impunity that prevailed for decades in Haiti".

"Failing to bring to justice those responsible will only lead to further human rights abuses," the Amnesty International official said.

Voodoo cult

Jean-Claude 'Baby Doc' Duvalier Took over presidency aged just 19 when his father, Haiti's authoritarian leader Francois "Papa Doc" Duvalier, died in 1971 Called himself "president-for-life" and ruled with an iron fist, aided by a brutal private militia known as the Tontons Macoutes Accused of corruption and human rights abuses that prompted more than 100,000 Haitians to flee the country during his presidency Ruled for 15 years before outbreak of popular protests led him to flee to France in 1986 Asked Haitian people for forgiveness for "errors" made during his rule in a 2007 radio interview Returned to Haiti as it was supposed to hold run-off election to choose successor to outgoing President Rene Preval, although vote has been postponed

Wearing a dark suit and tie, Mr Duvalier was greeted by a small group of supporters when he stepped off an Air France flight at Port-au-Prince airport.

Jean-Claude Duvalier was just 19 when he inherited the title of "president-for-life" from his father, the notorious Francois "Papa Doc" Duvalier, who had ruled Haiti since 1957.

He is accused of massive corruption, repression and human rights abuses during his 1971-1986 rule.

Critics allege he embezzled millions of dollars from the impoverished Caribbean nation, a charge he denies.

Like his father, he relied on a brutal private militia known as the "Tontons Macoutes", which controlled Haiti through violence and intimidation.

"Playboy" Baby Doc

"Papa Doc" reinforced his power with a fearsome personality cult based on Haiti's traditional voodoo religion, but "Baby Doc" was regarded as more of a playboy.

In 1986 he was forced to flee into exile by a popular uprising, as well as diplomatic pressure from the US.

Since then, he has lived in France, although he was never granted formal political asylum.

In a radio interview in 2007, he asked the Haitian people for forgiveness for "errors" made during his rule.

A small group of Duvalier loyalists have been campaigning to bring him home from exile.

His return to Haiti came on the day the country was supposed to hold the second round of elections to choose a successor to outgoing president Rene Preval.

But the vote has been postponed because of a dispute over which candidates should be on the ballot paper.

Provisional results of the 28 November first round provoked violent demonstrations when they were announced in December, and most observers said there was widespread fraud and intimidation.

Haiti is also struggling to recover from a massive earthquake a year ago which killed more than 250,000 people and left the capital, Port-au-Prince, in ruins.