Bill Clinton netted $1.6 million last year from a pair of for-profit education companies that caused controversy for the future president during Hillary Clinton's time as secretary of state.

Laureate Education paid Bill Clinton nearly $1.1 million in 2015, according to tax returns released by his wife's campaign Friday. GEMS Education, a Dubai-based firm, paid him more than $560,000.

Both companies are major donors to the Clinton Foundation.

Bill Clinton's lucrative consulting contracts with the corporations have raised questions about how closely his personal fortune is linked to his philanthropic activities.

What's more, the State Department handed Laureate's chairman taxpayer-funded grants under Hillary Clinton's watch.

Bill and Hillary Clinton Total Income Graphiq

Douglas Becker, CEO of Laureate, also heads a nonprofit group called the International Youth Foundation, which netted millions from the U.S. Agency for International Development in 2010. USAID is an arm of the State Department.

The Clintons have weathered criticism in the past for promoting affordable or free higher education while accepting a paycheck from one of the largest for-profit college education firms in the world.

Bill Clinton said he ended his time as the honorary chancellor of Laureate in April of last year, the same month Hillary Clinton launched her presidential bid.

Contracts with GEMS and Laureate have earned Bill Clinton more than $15 million. That sum padded the additional millions he pocketed from speaking fees thanks to engagements he booked around the world while Hillary Clinton served as the nation's chief diplomat.