Buenos Aires City security minister Marcelo D’Alessandro announced on Wednesday evening that he was resigning, months after chats apparently leaked from his phone appeared to show improper activity in his role. 

“Today, after seven years of work, management and sacrifice, I communicated to the chief of government my decision to take a step aside to become the plaintiff in the case investigating the illegal intelligence operation against me,” D’Alessandro said in a statement.

In January, he announced that he would take a leave of absence after a series of chats allegedly leaked from his phone implicated him in improper activity. He initially said that he would not resign, but announced on Wednesday that he would not resume his duties.

The chats appeared to show that he had been on a paid trip with judges and media business moguls to the Patagonian Estancia of British billionaire, Joe Lewis, and subsequently attempted to cover the trip up, sparking an investigation on charges that he had illegally received handouts.

On December 29, a second series of chats were leaked allegedly showing conversations between D’Alessandro and public figures including former intelligence chief Sylvia Majdalani, Supreme Court Justice Horacio Rosatti’s spokesman Silvio Robles, businessman Marcelo Violante, prosecutor Augusto Troncoso, and a deleted account understood to be the suspended prosecutor Juan Ignacio Bidone.

The chats appear to show D’Alessandro negotiating with Robles over where the dispute over federal tax shares would be handled and favoring Violante in public works tenders.

D’Alessandro has maintained that he is innocent and that the chats are fake. Buenos Aires City Mayor Horacio Rodríguez Larreta said: “The illegal intelligence operation against him that he has been dealing with takes time and energy for him to defend himself. For that reason, he has decided to take a step aside to fully dedicate himself to fighting that fight and protecting his family.”

D’Alessandro, who had been in his role since 2016, will be replaced by Eugenio Burzaco, a former deputy belonging to Rodríguez Larreta’s right-wing party Propuesta Republicana (PRO). Burzaco is a former chief of the Buenos Aires Metropolitan Police.