Four Peruvian entrepreneurs linked to Brazilian construction company Odebrecht were transferred from a Justice Palace's detention cell to Lima region's Ancon No. 1 prison facilities.
They will remain in jail while investigations are carried out as they await trial.
The measure is addressed to Fernando Gonzalo Camet Piccone, Jose Fernando Castillo Dibos, Hernando Alejandro Graña Acuña and Jose Alejandro Graña Miro Quesada.
On the other hand, Gonzalo Ferraro Rey was placed under house arrest. He is currently at a health center for his delicate health condition.
The order was issued by Judge Richard Concepcion Carhuancho, head of the First Preparatory Investigation Court.
It must be noted Anticorruption Prosecutor Hamilton Castro had warned the entrepreneurs posed a flight risk.
During the hearing, he said the persons under investigation belong to the most prominent business group in Peru and have financial resources to escape justice.
The jail terms against them are linked to collusion and money laundering charges.
According to the prosecutor, the firms gave part of their profits to the Brazilian conglomerate in exchange of a US$20 million bribe to ex-President and now fugitive Alejandro Toledo (for the award of a contract) to build sections 2 and 3 of the Southern Interoceanic Highway project.