Denver police spokesman Sonny Jackson said Thursday that officers went to the facility Aug. 13 after a report of an altercation involving Smith and another player in a pickup game. The other player, whose name wasn't available, isn't in the NBA.
The district attorney previously declined to pursue the complaint against Smith, but the investigation has been reopened because another witness came forward, Jackson said.
"We just want to evaluate it," Jackson said of the new information.
The Nuggets didn't immediately return a message to The Associated Press.
Smith, acquired by the Nuggets in July 2006 in a trade with the Chicago Bulls, spent time in Denver coach George Karl's doghouse this season as he struggled with his slumping performance and reduced playing time. He averaged 15.4 points per game.
His off-court woes have included serving 24 days in a New Jersey correctional facility last year after pleading guilty to reckless driving in a car crash that killed a friend. Smith was drafted out of high school by the New Orleans Hornets in 2004.