Cops Claim Damon Arnette Had Tampered Pill Filled W/ Meth Hidden In Sock

Damon Arnette attempted to conceal drugs on his body the night he was arrested, according to police in Texas ... who say the former first-round draft pick hid a pill stuffed with meth inside his sock.

The entire arrest is spelled out in court docs obtained by TMZ Sports, where officers document the stop ... from the time they pulled over the 27-year-old football player for speeding.

A Richardson (TX) police officer stopped Arnette for going 60 MPH in a 45 MPH zone in a white 2021 Dodge Challenger at 1:48 AM on January 6.

From the start, cops claim Damon, who told them he was a pro football player who had substance abuse issues in the past, was "unusually nervous and talkative."

Taking those factors into account, officers say they summoned a K9 to the scene ... and when the dog arrived, it signaled narcotics were present.

Arnette told officers there weren't drugs or weapons on him or in the car.

Since the dog alerted to the vehicle, officers began a search ... and discovered a loaded black Glock 20 10mm pistol under the passenger seat.

At that point, officers placed Arnette in handcuffs "due to his dishonesty."

Cops continued to search the Challenger, but came up empty. They then searched Damon.

Officers located a white and orange capsule with no markings inside Arnette's left sock, which the football player claimed was Adderall, an ADHD medicine, that had been prescribed by a doctor.

Cops say they were suspicious because of how the pill was hidden, and upon further inspection, they say it was clear the capsule had been tampered with as if it'd been "manually opened."

Officers researched Adderall, and concluded Arnette's pill wasn't consistent with the look of the actual medication. Cops popped open the pill and observed a "white, crystal-like substance," which they tested at the scene.

The results ... methamphetamine, according to police.

At that point, Arnette was officially placed under arrest, and transported to the city jail on drug and gun charges.

Despite how the situation looks, Arnette's lawyers say their client did nothing wrong ... insisting the pill was in fact medication prescribed by a physician.

If Arnette's version of the story is accurate, there's a good chance the case could go away ... it's the drugs that made the gun illegal. Legal drugs likely means a legal gun for Damon.

Reps for the former Raiders CB tell us they're working with local officials to resolve the matter.