LOS ANGELES — Los Angeles Clippers owner Donald Sterling’s team of lawyers has hired four private investigation firms to dig up dirt on the NBA’s former and current commissioners and its 29 other owners, said a person familiar with Sterling’s legal strategy.

Investigators were given a six-figure budget over the next 30 days to examine the league’s finances, allegations of previous discriminatory conduct and compensation to past Commissioner David Stern and current Commissioner Adam Silver, said the person who spoke to The Associated Press on Thursday night on condition of anonymity. The person wasn’t authorized to talk publicly.

The person said the investigators also are looking into whether other owners made any off-color jokes, or racist or sexist remarks.

“The gloves are off, as they say,” the person said. “Have them dig up all the dirt they can find.”

The 80-year-old Sterling is suing the NBA for $1 billion in federal court after the league tried to oust him as Clippers owner for making racist remarks to a girlfriend that were recorded and publicized. Silver fined him $2.5 million and banned him for life.