Some of the world’s biggest gambling tycoons — including Las Vegas kingpin Steve Wynn, Chicago slots magnate Neil Bluhm and MGM chairman James Murren — are going under the microscope as state investigators scrub their entire criminal, employment and financial histories, at a hefty price of at least $4.4 million, newly released records show.

The trio of gaming titans are among nearly 300 executives, officers and investors — tied to 11 separate proposed gambling developments — who are being screened by state gaming officials. Wynn is seeking a license for an Everett casino, MGM is planning a Springfield casino and Bluhm is vying for a slots license at an undisclosed location.

The background checks — by state police and hired-gun investigators — are expected to take up to six months as officials sift through more than 21,000 pages of filings. Each project’s comprehensive background check has an initial cost of $400,000, which is funded through preliminary license fees paid by casino companies.

In addition to Bluhm, Murren and Wynn, others connected to various casino and slots parlors projects who are under scrutiny include:

•  Boston concessions king Joe O’Donnell, Caesars CEO Gary Loveman and Suffolk Downs owner Richard Fields, who have teamed up to build a $1 billion casino at the East Boston racetrack;

• Stanley Fulton, a Las Vegas slots king, and Dartmouth investor Alfred Ross, who are vying for a slots facility at Plainridge Racecourse in Plainville;

•  William Warner, CEO of Vegas-based Warner Gaming, who is part of a team seeking a license for a Milford casino; and

•   Raynham Park owner Geo rge Carney, and Anthony Ricci, CEO of Philadelphia-based Parx Gaming, who have partnered on a proposed slots palace at the Route 138 racetrack.

While the state gaming commission has repeatedly pledged “transparency,” most details of screenings will be kept private.

“The investigations …will cover their employment history, criminal records, education, stockholdings and financial suitability, among other areas,” Massachusetts Gaming Commission spokeswoman Elaine Driscoll said. “Much of the information is highly personal and of the type that the law does not permit the commission to disclose.”

State rules require all “qualifiers” — officers, executives or anyone else with a financial interest in a proposed gaming facility — to go through an extensive background check.

Of the 11 gaming hopefuls, MGM, which is vying for a casino in Springfield, has one of the longest list of qualifiers, with more than 30 officials and 12 different corporations, including some located in Dubai and the Cayman Islands.