NEW YORK -- The FBI is investigating allegations that a veteran NBA referee bet on basketball games over the past two seasons, including ones in which he officiated, according to a law enforcement official.

Among other things, authorities are examining whether the referee made calls to affect the point spread in games on which he or associates had wagered.

The law enforcement official, who spoke to the AP on Friday on condition of anonymity, said the referee was aware of the investigation and had made arrangements to surrender as early as next week to face charges.

The probe, which began recently, also involves allegations that the referee had connections to organized crime associates. Other arrests are expected, the official said.

According to the official, the referee had a gambling problem and was approached by low-level mob associates through an acquaintance.

The law enforcement official, who did not identify the referee, said the bets involved thousands of dollars and were made on games during the 2005-2006 and 2006-2007 seasons.

The law enforcement is familiar with the investigation but was not authorized to speak publicly about it because of the ongoing investigation.

The existence of the investigation was first disclosed Friday by the New York Post.