The son of Colombian president Gustavo Petro was arrested on Saturday morning on accusations of money laundering and illicit gain, the nation’s attorney general said.

Prosecutors started investigating Nicolás Petro in March after his ex-wife Daysuris Vásquez gave an interview alleging he took money from criminals. Both Nicolás and Vásquez were detained on Saturday for events that took place starting last year, the attorney general’s office said.

“As president I assure you that the attorney general will have all guarantees to proceed according to law” Petro tweeted on Saturday morning. “As a person and a father, so much self-destruction and the fact that one of my sons goes to jail hurts me a lot.”

Read more: Colombian Prosecutors to Probe Allegations into President’s Son

The accusations reaching the president’s inner circle take place at the start of Colombia’s new legislative session in which Petro hopes to push through some of his most important reforms. The scandal could also impact regional elections set for late October, in which Petro’s party will fight for the nation’s top five mayoralties.

Earlier this year authorities also opened an investigation into the president’s brother, Juan Fernando Petro, over alleged payments from cocaine traffickers who wish to negotiate with the government.