SEOUL - South Korea's ousted president Park Geun-hye spent her first day in custody on Friday after a court ordered her arrest.

The former head of state stared straight ahead, apparently trying to maintain her composure, as she was driven to the Seoul Detention Center through a barrage of camera flashes shortly before dawn.

After a marathon hearing on Thursday, a court in the capital ordered Park's arrest in connection with the corruption scandal that brought millions of people onto the streets and saw her impeached.

Prosecutors have yet to specify the formal charges against her, but they have previously said she is suspected of bribery, abuse of authority, coercion and leaking government secrets.

"It is justifiable and necessary to arrest (Park), as key charges were justified and there is risk of evidence being destroyed," the court said in a statement.

The decision made Park, 65, the third former leader to be arrested over corruption in Asia's fourth-largest economy, where politics and big business have long been closely tied.

The liberal Democratic Party, which is favored to win the election on May 9 to choose Park's successor, said in a statement that the move showed "all are equal before the law".

"We hope today's landmark decision will provide fresh momentum in revealing the truth about the scandal of an unprecedented scale," it added.

According to a Gallup Korea survey released on Friday, Moon Jae-in, former head of the party, garnered 31 percent of public support this week, unchanged from last week.

Park's own Liberty Korea party - which has changed its name in an effort to distance itself from her - called the arrest "regrettable".

Loyalist lawmaker and presidential hopeful Kim Jin-tae was furious, calling it "the death knell for the country's rule of law".

AFP-Xinhua

South Korea's ousted leader Park Geun-hye leaves the prosecutors' office as she is transferred to a detention house in Seoul on Friday. Xinhua