The head of the Massachusetts Gaming Commission said the state's new casino law potentially concentrates a lot of power in a mayor’s hands.

Under the state's new gambling law, developers who want to build a casino in a city or town must win approval from voters in a referendum. But Massachusetts Gaming Commissioner Steve Crosby said the mayor’s office controls when and how many casino proposals go to the ballot.

"The mayor’s the mayor. The mayor can run this the way he wants to under the law. And you know, that’s the way the system works," he said.

Springfield Mayor Dominic Sarno is considering proposals from at least four casino operators including Ameristar, MGM, Hard Rock and Penn National Gaming. But it is likely that only one proposal will be put before voters.

Crosby said nobody foresaw this situation, but it’s technically legal. 

“I don’t think anybody particularly anticipated that there would be multiple sites in a city. Could happen in Boston too — if somebody came along and said, 'I want to do one in Dorchester,' basically Mayor Menino would have the right to say ‘No, I’m not going to negotiate a host community with Dorchester, I’m just going to do one with East Boston.’”

Mayors and other municipal officials also have the power to keep a casino out all together.

In Foxborough earlier this year, the Board of Selectmen stonewalled a proposal from Las Vegas mogul Steve Wynn and New England Patriots owner Bob Kraft. The proposal never went to the voters. 

Crosby said all he can do is urge mayors to be more transparent. But in the end, he said the five-member Gaming Commission will have the final say on which companies get the lucrative casino licenses.