Peruvian opposition leader Keiko Fujimori will be jailed preventively for 36 months while money-laundering charges against her are investigated, a judge ruled Wednesday.

There were "sufficient elements" to indicate that Fujimori headed a criminal network to launder illicit funds that the corruption-tarnished Brazilian construction company Odebrecht contributed to her 2011 presidential election campaign, judge Richard Concepcion Carhuancho said.

The 43-year-old leader of the main opposition party Popular Force (FP) ran a "power structure for others to commit these crimes," the judge added.

After a hearing which lasted over seven hours, Concepcion Carhuancho ruled that Fujimori was at risk of fleeing and the power of FP in parliament risked obstructing the work of the judiciary.

The judge made a surprise announcement in the morning when he said he would dedicate the day to solving the Fujimori case.

Fujimori received the ruling with relative calm and embraced her husband, Mark Vito Villanella, who was on the verge of tears.

She was then escorted out by uniformed police women and taken to the The National Penitentiary Institute.

"What I want to say to my wife is: they can make us suffer as they did today, but we will never give up," said Villanella.

"What we saw today is a clear show of judicial bias. There is no basis [for preventative detention]," he added.

Fujimori had been arrested on charges of money laundering on October 10 and released eight days later.

The FP leader denies the charges and claims that Concepcion Carhuancho and prosecutor Jose Domingo Perez are obsessed with her and want to "annihilate" her political career.

If convicted, the daughter of former president Alberto Fujimori could be sentenced to 10 to 16 years.

Her arrest came a week after the Supreme Court overturned a pardon that had been granted to her father, former president Alberto Fujimori, who is now due to serve the 15 years that remain from his 25-year prison sentence for human rights abuses. He is currently under arrest at a Lima medical clinic.