ATLANTIC CITY, N.J. (AP) - The nation's professional sports leagues may have to dig deep to come up with proof of their opposition to sports betting through the years.

Major League Baseball, the National Football League, National Hockey League and National Basketball Association, along with the NCAA, are suing New Jersey to try to block the state from offering legalized sports betting in defiance of a federal ban on it here.

But court filings show that as part of that lawsuit, the leagues may have to turn over documents regarding the potential impact of sports betting, fantasy sports leagues and even "March Madness" office pools on consumer perceptions of the integrity of the games.

New Jersey is also seeking depositions from the commissioners of each of the leagues. The state plans to start licensing sports betting in January.

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