One of the richest men in Chile, Julio Ponce, was been fined $70 million by the regulator of the Chilean stock exchange for illegal share trading.

Ponce, the ex-husband of the daughter of the infamous former Chilean dictator Augusto Pinochet, is the chairman of Sociedad Quimica y Minera, which is the world's biggest producer of iodine, lithium and potassium, according to BBC.

The charges against Ponce claim that he and his business partners made money at the expense of company shareholders. The Chilean stock exchange fined Ponce and seven associates a total of $164 million, the highest fine ever levied in the country.

Ponce is alleged to have led a scheme that used insider knowledge to buy stocks at below-market prices in order to sell them at a profit. BBC reporter Gideon Long says that many of those transactions went through LarrainVial, Chile's biggest brokerage firm, which also was fined.

"This scheme directly and economically benefited the president of the holding companies, Mr. Julio Ponce Lerou, and people close to him that participated in said scheme in diverse ways ... in the economic detriment and against the interests of the holding companies, which had other investors such as pension and investment funds," court documents say, Reuters reported.

LarrainVial and the eight men charged in this case have 10 days to either pay the fine or appeal the decision in court.

Ponce was previously married to Pinochet's daughter Veronica for 22 years and during that time he built his wealth as the director of several state-owned companies during Pinochet's military dictatorship in the 1980s. When Pinochet's rule was coming to an end, Ponce benefited financially from the privatization of his mining company.

This year, Forbes listed Ponce as one of the 1,000 richest people in the world, with a net worth of $3.3 billion.