A person with knowledge of Los Angeles Clippers owner Donald Sterling's legal strategy says his team of lawyers has hired four private investigation firms to dig up dirt on the NBA's former and current commissioners and its 29 owners.

The individual, who wasn't authorized to talk publicly, says 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. They're also looking into whether other owners ever made any off-color jokes, or racist or sexist remarks.

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 publicized.