The Melbourne Storm have been forced to address “rumours and innuendo” about their salary cap following confirmation that they had secured an extension for Cameron Munster despite a significantly higher financial offer from the NRL's incoming franchise.

The Dolphins had amassed a huge four-year, $5.6 million offer for Munster that would have made him the highest-paid player in the game, leaving the Dolphins without a high-profile name after they were originally considered a good chance of landing the Storm five-eighth.

But now that Munster has elected to stay with the Storm, the club is facing allegations and rumours about salary cap manipulation, akin to the methods that saw them stripped of multiple titles by the NRL over a decade ago.

“First of all, everything we've done in terms of getting Cameron on board is cap-related and 100 per cent above board,” Storm chairman Matt Tripp advised News Corp.

“The last thing I want to do is cause any drama by having our club, given what we've been through, dragged through the mud again. We just don't operate that way.

“There are always going to be rumours and innuendo and rubbish thrown at us, particularly from those that miss out on players like Cameron.

“I know where these rumours would be coming from, but that's all they are.”

The Dolphins meanwhile are already preparing to move on, with rumours suggesting they'll now chase either of Parramatta halves combo Dylan Brown and Mitchell Moses after also missing out on Ben Hunt, who will stay with the Dragons.

“We found out (about Munster's decision) just before it was announced by Melbourne,” Dolphins boss Terry Reader told NewsCorp.

“We still have plenty of firepower in our salary cap to make sure we bring in more quality players.

“It's still been a positive week for us. We've been able to sign Hamiso (Tabuai-Fidow), he's a massive signing for the club.

“The best thing about this process now is that it's all over. We're happy that Cam has made a decision. Good luck to him and we're not concerned, we'll move on.”