The constitutional complaint is most serious legal development yet against embattled President Pedro Castillo.

The legal filing on Tuesday was the most aggressive push yet against the president, who took office only a year ago and is already facing five separate criminal investigations, and has survived two impeachment attempts.

“We have found very serious indications of a criminal organisation that has taken roots in the government,” Attorney General Patricia Benavides said.

Castillo has faced repeated challenges over whether he has used his presidency to benefit himself and his family. He denies any wrongdoing.

While Peruvian presidents normally have immunity against criminal cases, a constitutional complaint allows Congress to carry out its own trial. But some observers have noted that prosecuting an incumbent president will be constitutionally complex.

The outcome of that trial could lead to Castillo’s suspension from office; it requires fewer votes than a full-fledged impeachment trial.

Beginning of the end for Pedro Castillo’s presidency? Prosecutors just filed a constitutional accusation against him for corruption. The evidence appears overwhelming but prosecuting a sitting president is uncharted legal territory for Peru and constitutionally controversial. https://t.co/6LIospteB5

— Simeon Tegel (@SimeonTegel) October 11, 2022

Prosecutors said the five people detained on Tuesday had helped Castillo’s former secretary avoid detention for corruption charges earlier this year.

Among those detained are Auner Vasquez and Biberto Castillo, who worked at Peru’s government palace, where the president’s office operates.

The prosecutors also ordered raids that were part of a separate operation, including raiding a house inhabited by Castillo’s sister as well as the homes of six lawmakers who have supported his administration.

The president’s sister-in-law, Yenifer Paredes, was given 30 months of pre-trial detention in August. Paredes has not been charged with a crime but will spend time in detention as prosecutors continue their investigation.

Prosecutors allege she was part of a group that engaged in assigning public contracts to allies of Castillo in their home region of Cajamarca, in the Peruvian Andes.

The government said it would issue a statement later on Tuesday on the detention and the raids.

Castillo condemned the raid on his sister’s home in a tweet, calling it an “abusive act”.