EXCLUSIVE

Detroit Pistons player Avery Bradley entered into a confidentiality agreement with a reality star who accused him of sexual assault earlier this year -- and at one point, negotiations got as high as $400k, TMZ Sports has learned.

But Bradley's attorney tells TMZ Sports he adamantly denies all wrongdoing -- and only entered into the agreement to prevent false information from being made public.

Here's what we know ... the allegation stems from an incident on May 23 in Cleveland, Ohio. The woman involved claimed Bradley sexually assaulted her while she was passed out drunk.

Bradley was a member of the Boston Celtics at the time of the incident. The Celtics were in Cleveland to play the Cavs in the Eastern Conference Finals.

After the incident, the woman contacted Bradley and accused him of assaulting her. The two sides came together to work out a deal to keep her quiet and prevent her from releasing any video, photos or audio.

At one point in the negotiations, the parties considered resolving the matter for $400,000 ... but it's unclear what number Bradley ultimately agreed to pay. We're told the final figure was high.

We spoke with Bradley's attorney Brian Wolf of Lavely & Singer who tells us, "Mr. Bradley absolutely denies having engaged in wrongdoing whatsoever. The confidentiality agreement specifically refutes and denies the validity of all allegations of any wrongful conduct by Mr. Bradley. The sole purpose of the agreement was to protect the reputation and privacy of Mr. Bradley and his family."