Federal and state grand juries have indicted three owners of the waterfront land that Wynn Resorts plans to develop into a $1.6 billion resort casino, alleging they concealed from Wynn and state regulators that one of the owners is a convicted felon.

The U.S. Attorney's office in Boston unsealed indictments Thursday alleging that Charles Lightbody, Dustin DeNunzio and Anthony Gattineri concealed the interest that Lightbody, a convicted felon and reputed New England mafia associate, had in the land in Everett, a Boston suburb. The three are charged with conspiracy to commit wire fraud, wire fraud and aiding and abetting.

The state indictments also unsealed Thursday charge the three with impeding a gaming investigation, conspiracy and tampering with evidence.

Wynn Resorts won the lucrative Boston-area casino license in September.

Tim Flaherty, one of Lightbody's attorneys, said the indictment is based on "speculation and conjecture" and that his client "steadfastly professes his innocence." It's not clear who represents the others.

Lightbody made an initial federal court appearance Thursday and was ordered held until his next court date on Tuesday. The others were to make initial court appearances Thursday.

Federal prosecutors said the men held a financial interest in FBT Everett Realty LLC, which held title to the proposed casino land, but claimed that Lightbody transferred his interest to Gattineri for a $1.7 million promissory note. Prosecutors alleged they created fraudulent documents to support their story, and sent Wynn Resorts an email falsely saying that DeNunzio, Gattineri and a third person were the only ones with a financial interest. Prosecutors said that DeNunzio, Gattineri and Lightbody also misled investigators for the Massachusetts Gaming Commission about Lightbody's interest.

The state indictment includes similar allegations and also charges Lightbody with assaulting a man during a casino election rally in Revere in October 2013. The three will be arraigned on the state charges at a later date.