By Marco Aquino

LIMA (Reuters) -Peruvian authorities said on Friday that they had launched an investigation into President Dina Boluarte for disbanding a special police force that had been investigating her brother, who was detained earlier in the day.

Nicanor Boluarte and the president's lawyer were arrested as part of a probe into alleged influence peddling, ramping up pressure on the Andean country's leader, who is already being investigated over how she got pricey Rolex watches and jewelry.

Peru's attorney general's office said it was now looking into a potential abuse of authority by President Boluarte and Interior Minister Walter Ortiz for dissolving the police unit.

Earlier in the day, Attorney General Juan Carlos Villena said in an a government act that the authority was weighing its options and demanded the police unit be reinstated "immediately."

Authorities searched more than 20 properties on Friday, including the Lima home of Nicanor Boluarte, who is accused of leading a criminal organization that influences the appointment of people in high positions on power.

Across town, a team of prosecutors and police raided the home of Boluarte's lawyer Mateo Castaneda, who is advising her in the case of alleged illicit enrichment involving the watches and jewelry. Boluarte has denied the accusations.

The president's brother, along with other unnamed suspects, will remain in preliminary detention for 10 days, Peru's justice department said.

A spokesman for President Boluarte told a press conference on Friday evening that the police unit had been dissolved for failure to comply with administrative norms and that the government respected the laws and judicial autonomy.

Nicanor Boluarte, as he was transferred by the police to a judicial unit, denied the allegations to reporters. "I am innocent... I deny absolutely everything," he said.

Peru, the world's number two exporter and once one of South America's most attractive investment locations, has been hit by political unrest in recent years, with six presidents in as many years and regular corruption probes and impeachments.