Peru's Constitutional Tribunal on Monday ordered the release of opposition leader Keiko Fujimori, jailed last year for alleged money laundering and receiving illegal contributions from Brazilian construction company Odebrecht.

The members of Peru's top court decided to release Fujimori by a narrow margin of four votes in favor versus three against, the body's president Ernesto Blume said at a press conference.

Fujimori has been serving an 18-month pre-trial sentence since October 2018 after prosecutors said she led a criminal organization and received millions of dollars from Odebrecht during her 2011 election campaign.

She denies the accusations.

"The court has not passed judgment on the substantive issue in the case of citizen Keiko Fujimori, and has not declared her acquittal or condemned her," Blume said.

Fujimori is the daughter of the country's authoritarian ex-President Alberto Fujimori, who is serving a 25-year sentence for human rights crimes and graft.

The decision comes as the country prepares to hold legislative elections on January 26 after President Martín Vizcarra dissolved Congress amid a battle with lawmakers over his anti-graft campaign. Keiko Fujimori's Popular Force party had held a majority in Congress before its dissolution. 

Popular Force, a conservative right-wing group, has announced it will participate in the January elections, but Fujimori is not expected to take part.