Mexican President Enrique Pena Nieto has ordered the start of an investigation into the purchases of his home, a house bought by his wife, and the home of his finance minister.

In an effort to combat accusations of an alleged conflict of interest, Pena Nieto, who has consistently denied that there had ever been a conflict of interest, has asked the federal comptroller Virgilio Andrade to investigate the purchases of these luxury houses from government contractors, BBC reports.

Critics of this move were quick to point out that the president should have selected an independent body to conduct the probe.

In 2014, once the information that Pena Nieto's wife Angelica Rivera had bought a luxury home from a subsidiary of Mexican company Grupo Higa, a scandal broke out in the nation. Rivera claimed that she had bought the house with her own finances, and that those finances were independent from those she shared with her husband. Amid public outrage, she sold the house.

Unscrupulous business dealings seemed obvious to observers as Grupo Higa was part of a consortium that was awarded a multi-billion-dollar contract to build a bullet train in Mexico. The project for the bullet train has, due to budget cuts, has been shelved.

Pena Nieto's Finance Minister, Luis Videgaray, also purchased a house from the same company.

The money scandal grew when it came to light that during his time as governor, Pena Nieto bought a home from another government contractor as well.

All three of the people involved in the scandal deny they have done anything wrong.

Critics of Pena Nieto’s recent move point out that Pena Nieto has tasked a government department with the investigation and then named himself its new chief.

Before the recent appointment of Virgilio Andrade Martinez, the post of director of Mexico's Public Administration Department, the body charged with the probe, had been vacant for two years.