Authorities have arrested two more key allies of imprisoned Peruvian opposition leader Keiko Fujimori, who is accused of hiding illegal campaign contributions from a Brazilian construction company.

Pier Figari and Ana Herz were detained while marching with about 1,500 people who were demanding the release of Fujimori and several other members of her Popular Force party on Monday.

Figari and Herz have worked closely with Fujimori for more than a decade. Prosecutors have accused them of "aiding a criminal organization."

Supporters of Peru's former President Alberto Fujimori and his daughter Keiko march with a poster of them that reads in Spanish: "This is not justice, it's revenge" in Lima, Peru, Monday, Oct. 15, 2018. Keiko was detained last week as part of a money-laundering investigation and a judge ordered her father returned to jail to finish a 25-year sentence for human rights abuses. (AP PhotoMartin Mejia)

Supporters of Peru's former President Alberto Fujimori and his daughter Keiko march with a poster of them that reads in Spanish: "This is not justice, it's revenge" in Lima, Peru, Monday, Oct. 15, 2018. Keiko was detained last week as part of a money-laundering investigation and a judge ordered her father returned to jail to finish a 25-year sentence for human rights abuses. (AP PhotoMartin Mejia)

A spokeswoman for the party said the arrests were part of a political witchhunt against Fujimori and her powerful political movement, which holds a majority of seats in Peru's Congress.

Keiko Fujimori was arrested Wednesday as she visited a prosecutor's office to testify in a money laundering investigation.

Supporters of Peru's former President Alberto Fujimori and his daughter Keiko, march in Lima, Peru, Monday, Oct. 15, 2018. Keiko was detained last week as part of a money-laundering investigation and a judge ordered her father return to jail to finish a 25-year sentence for human rights abuses. (AP PhotoMartin Mejia)

Supporters of Peru's former President Alberto Fujimori and his daughter Keiko, march in Lima, Peru, Monday, Oct. 15, 2018. Keiko was detained last week as part of a money-laundering investigation and a judge ordered her father return to jail to finish a 25-year sentence for human rights abuses. (AP PhotoMartin Mejia)