Melbourne Storm players bunkered down after training on Thursday as speculation mounted the premiership favourites could lose competition points over a salary cap breach.

NRL chief executive David Gallop called a press conference for 4pm at NRL HQ in Sydney.

A senior Storm player had been due to speak to media following their skills session at Princes Park in Melbourne.

But the team hurriedly left the field in a group led by skipper Cameron Smith - said to be for a team meeting - and did not return.

Storm coach Craig Bellamy also left the session early. He was understood to have been summoned to a meeting, and left the training session to his assistants to run.

Storm chairman Rob Moodie and chief executive Matt Hanson were in Sydney, where they were understood to be meeting with the NRL.

The events came after several bookmakers suspending betting on the NRL wooden spoon following a stream of bets for premier Melbourne to finish last.

Sportingbet Australia and SportsAlive both shut down their wooden spoon markets after fielding several bets at 250-1, with punters standing to win $10,000 on single bets.

TAB Sportsbet left its market open, but wound the Storm into 20-1 for the spoon after taking a $200 bet at 200-1 for a collect of $40,000 on Wednesday night.

The Storm, currently fourth on the ladder, have been the subject of a salary cap investigation.

The club last month opened its books to salary cap auditor Ian Schubert after it emerged the NRL was concerned with several issues regarding player payments, including a third-party television deal involving skipper Smith.

"We took three bets to win $10,000 and another to win $8000 for the Storm to win the wooden spoon all within 10 minutes of each other this morning," said Sportingbet Australia spokesman Bill Richmond.

"You don't take a series of bets like that unless someone knows something and we have suspended betting on the wooden spoon as a result.

"Melbourne is now our worst result for the wooden spoon despite the fact they are premiership favourites."

Another bookmaker - sportsbet.com.au - also suspended betting on the wooden spoon and on teams to miss the top eight.

"Before betting was suspended we took more than 30 bets this morning on NRL teams to miss the Final 8. Every single one of those bets was on the Melbourne Storm at $7," spokesman Haydn Lane said.

"We also took a bet to win $50,000 and several others to win more than $10,000 each on the Storm for the spoon in quick succession."

TABSportsbet spokesman Glenn Munsie said he didn't think much of the initial $200 bet on Wednesday night until further bets followed on Thursday morning.

"The spark starts, becomes a brushfire, becomes a bushfire," Munsie said.

"It all started in a couple of places this morning and they're now coming from everywhere."

In 2002, Canterbury - who were on top of the ladder at the time - finished last after having 37 competition points stripped by the NRL over salary cap breaches.