The Costa Rican Public Prosecutor's Office has opened an "influence peddling" investigation into President Rodrigo Chaves and several members of his government, the agency told AFP on Tuesday.

The probe follows a criminal complaint lodged July 25 by businessman Leonel Baruch, who accused Chaves of interfering in his divorce and child custody proceedings.

The Public Prosecutor's Office said in a short statement that it had opened the investigation "as a result of the complaint filed by Mr Baruch," president of Costa Rican bank BCT Corporation and a board member of CR Hoy, a media outlet critical of Chaves.

Others included in the investigation are Minister of Communication Jorge Rodriguez, presidential advisor Gabriel Vargas and Baruch's ex-wife, Yafit Ohana.

Baruch claims his ex-wife received favorable government treatment in the divorce after contributing to a social media video used by the Minister of Finance, Nogui Acosta, to denounce an alleged case of tax evasion.

The dispute between Baruch and Chaves came to light through a statement sent by the businessman's lawyer in which he confirmed that "there is no other alternative than the legal actions taken today against the president of the republic and other participants in such actions."

The crime of influence peddling is punishable in Costa Rica with two to five years imprisonment.

The case is "in a private stage," the Public Prosecutor's Office said, meaning no further information can be provided.

This is the second investigation opened against Chaves by the office in less than a month.

On July 17, it opened an official probe into alleged "abuse of power," after Chaves traveled to Latvia, the home country of his wife, after an official trip to Belgium.