PHILADELPHIA - As the result of an incident that now threatens to rival the length of Rajon Rondo [stats]’s just-completed agreement on a contract extension, the Celtics [team stats] point guard’s verbal beef with New Orleans Hornets star Chris Paul has taken on an extended life.

A league official confirmed yesterday that the NBA is investigating the incessant trash talking between the two guards during the C’s win Sunday at the Garden, a development that Rondo chose to pass on without a comment.