Fujimori, the daughter of disgraced and jailed former president Alberto Fujimori, was herself incarcerated on October 31 last year when she was ordered to be held in pre-trial detention for up to 3 years.
She is accused of accepting $1.2 million in illicit party funding from Odebrecht for her 2011 presidential campaign. (READ: Peru court orders Fujimori detention in graft probe)
The court was due to make a decision on her possible release on Friday but said its 5 magistrates could not come to an agreement.
"There has been no resolution," said the court's president Hugo Principe in a session that lasted less than 5 minutes.
He said the court would continue to discuss Fujimori's case.
In order to settle the case, the court's permanent chamber must appoint a 6th judge but it may take up to four months to reach an agreement, a judicial source told Agence France-Presse.
Keiko, 44, was not in court but followed the brief proceedings by conference call from the Chorrillos women's prison in southern Lima.
Prosecutors have accused a total of 11 people linked to Fujimori's Popular Force party of running a criminal organization to raise funding for her 2011 campaign.
Odebrecht has admitted paying at least $29 million in bribes to Peruvian officials since 2004.
Three former presidents are being investigated over Odebrecht while a 4th, Alan Garcia, committed suicide in April after police arrived at his house to arrest him for money laundering. – Rappler.com