Morales denies any wrongdoing in the more than $400 million worth of state contracts with China CAMC Engineering Co. Ltd. but says the State Controller's Office should determine if there were irregularities. The projects include a potassium plant and reservoirs.
He recently acknowledged a relationship in 2007 with Gabriela Zapata, who's a senior executive for CAMC in Bolivia.
The government last month cancelled a railroad track contract with the company and officials say it proves there's no favoritism.
Revelation of the relationship by a local journalist came less than a month before a national referendum on whether Morales should be allowed to seek a fourth term in office.
Panel to probe into Pappu’s infra contracts