Negotiations for bookmaker Tom Waterhouse to become an official sponsor of the National Rugby League (NRL) have broken down, with both parties walking away from the proposed deal.

"We failed to reach agreement around terms with Tom Waterhouse," the NRL's general manager for strategy, Shane Mattiske, has told the ABC's Four Corners program in an interview to be broadcast tonight.

Media reports earlier this year widely speculated the NRL had clinched a deal with Waterhouse after the high-profile bookmaker became a key advertiser for Channel 9's NRL coverage.

The combined NRL-Channel 9 deal was reportedly costing Waterhouse $50 million over five years.

But the NRL never concluded its deal with Waterhouse despite him emerging as the preferred bidder to become an official sponsor.

Key points: Waterhouse, NRL end sponsorship talks

Waterhouse, NRL end sponsorship talks Deal with NRL, Ch9 costed at $50m

Deal with NRL, Ch9 costed at $50m But Waterhouse's deal with Ch9 unaffected

Deal with Nine stays

Tabcorp had previously been the NRL's sports betting sponsor.

The breakdown in talks between Waterhouse and the NRL does not affect the bookmaker's deal with Channel 9.

"We've been negotiating with Tom since the early part of the year and at our commission meeting on April 19 we reported that we had failed to reach an agreement," Mr Mattiske told Four Corners.

The breakdown in negotiations came after controversy erupted over Mr Waterhouse's sports betting promotions during Channel 9's NRL broadcasts.

The NRL insists the breakdown was not a result of the public backlash against Mr Waterhouse after he appeared on Channel 9's expert commentary panel in March.

Tonight's Four Corners investigates the big changes underway in the sports betting business, from Mr Waterhouse to his global competitors and the political backlash against it.