9:31 AM -- All 10 suspects -- including the 4 coaches -- have now been arrested, officials say.

8:57 AM PT -- The U.S. Attorney's Office is about to hold a news conference to explain the charges. The conference is set to begin in a few minutes.

The FBI claims Jim Gatto -- the Director of Global Marketing for Adidas Basketball -- paid hundreds of thousands of dollars in bribes to funnel top prospects to Adidas sponsored colleges ... including Louisville.

It's all part of a massive probe into corruption in NCAA basketball -- spelled out in 3 separate criminal complaints.

One of the probes centered around Auburn assistant coach Chuck Person, who allegedly took thousands of dollars in bribes to steer players to a financial advisor and a high-end suit-maker.

The 3rd probe included USC assistant coach Tony Bland, Oklahoma State coach Lamont Evans and Book Richardson from the University of Arizona.

In total, we're told 10 people are facing charges. Eight of those people have been arrested.

It's all in court docs filed by the U.S. Attorney's Office for the Southern District of NY and obtained by TMZ Sports.

First, Gatto ...

In the documents, the FBI says Gatto tried to pay one player and his family $100,000 to get him to a school of Gatto's choice. Another player got $150k with the expectation that the player would sign with Adidas when he went to the NBA.

In the docs, the FBI says a coach at a major college in Florida told Gatto that he needed to pay a top player $150k so the player wouldn't attend another D1 school sponsored by a rival apparel company.

The coach allegedly told Gatto that the rival clothing company had also offered the player a "substantial sum of money."

The FBI says it has wiretapped phone calls catching Gatto and his conspirators in the act.

The FBI spells it out ...

"The investigation has revealed multiple instances of bribes paid by athlete advisors, including financial advisors and business managers, as well as high-level apparel company employees, and facilitated by coaches employed by NCAA division 1 universities, to student-athletes playing at or bound for NCAA D-1 universities, and the families of such athletes, in exchange for a commitment by those athletes to matriculate at a specific university and a promise to ultimately sign agreements to be represented by the bribe-payors once the athletes enter the NBA."

As for the case against Chuck Person, the FBI says he collected about $91,500 in bribes in exchange for funneling Auburn players to a particular financial advisor and a high-end suit maker, Rashan Michel.

The FBI says Person would use a portion of the bribes to pay off the families of high-priority recruits.

In one part of the documents, the FBI says Chuck met with a player and counseled him about how players secretly get away with NCAA violations.

He allegedly told one player, "The most important part is that you ... don't say nothing to anybody ... don't share with your sisters, don't share with any of the teammates, that's very important 'cause this is a violation ... of rules. But this is how the NBA players get it done."

"They get early relationships, and they form partnerships, they form trust, you get to know [financial advisor], you get to know Rashan a lot and like Rashan can get you suits and stuff ... you'll start looking like an NBA ball player, that's what you are."