Multiple investigations by FBI and the US Attorney’s Office are underway involving potential corruption charges against the Clinton Foundation, according to a former senior law enforcement official.

A set of investigations into Clinton Foundation have been initiated by a joint effort of Federal Bureau of Investigation and various US Attorneys Offices. The investigations include potential corruption charges, according to the former official who has direct knowledge of the activities.

The involvement of the US Attorney Office is a major departure from other centralized FBI investigations. Previously, FBI performed such investigations on its own.

Now, the New-York based probe is led by Preet Bharara, the U.S. attorney for the Southern District of New York, who is famous for his prosecutorial aggressiveness, which has led to a large number of convictions of banks, hedge funds and Wall Street insiders.

According to Bharara's official biography, he "has applied renewed focus on large-scale, sophisticated financial frauds by creating two new units — the Complex Frauds Unit and the complementary Civil Frauds Unit."

"The Civil Frauds Unit has collected close to $500 million in settlements since its inception, including multi-million dollar settlements with Deutsche Bank and CitiMortgage for faulty lending practices and other fraudulent conduct," the biography says.

Bharara is best known for securing convictions of prominent political figures, including former New York State Assembly Speaker Sheldon Silver, who was convicted of accepting $4 million in exchange for helping a cancer researcher and two real estate developers, and New York Republican Majority Leader Dean Skelos, who was sentenced to five years in prison for corruption.

According to the unnamed senior law enforcement official, the involvement of the U.S. Attorney's Office "would be seen by agents as a positive development as prosecutors there are generally thought to be more aggressive than the career lawyers within the Department of Justice."

Earlier this week it was revealed that the Obama administration rejected earlier requests from three FBI field offices that had hoped to open corruption cases involving the Clinton Foundation. The FBI asked the DOJ to open an investigation into a potential pay-for-play relationship between the State Department and the Clinton Foundation, which spends a very small fraction of its funds on actual charity work, but the DOJ wasn't interested — saying it had tried and failed to probe the organization in 2015, according to media reports.

In its 15 years of operations, the Clinton Foundation, officially known as the Bill, Hillary and Chelsea Clinton Foundation, has collected up to $2 billion from donors, according to The Washington Post. The donors include a wide range of the world's wealthiest people: Eastern European tycoons, Arab Sheiks, African mining magnates, hedge fund billionaires and Wall Street firms.