FARMINGDALE — A state election law may prevent town officials from bringing a proposed tax break for a natural gas pipeline back to a referendum vote in June, a county official has cautioned selectmen.

Ken Young Jr., executive director of Kennebec Valley Council of Governments, has pointed out that a section of state law the town might have adopted says that voters must approve a secret ballot item 90 days before the annual Town Meeting unless the community has its own rules.

Selectmen had scheduled the tax break vote for June 22, the day before the annual Town Meeting. Farmingdale voters already rejected the tax break at a special meeting in December.

Board of Selectmen Chairman David Sirois told selectmen Wednesday night that the town’s attorney, Mary Denison, will need to research the matter.

“It doesn’t make sense to have a referendum if it can be easily challenged on those grounds,” Sirois said.

Town officials said Thursday they were still researching the issue and did not yet have an opinion from Denison.

A public hearing on the tax break — a tax increment financing district — is scheduled to be held Tuesday, May 8, at Hall-Dale High School, depending on Denison’s opinion.

Selectmen have asked state officials to attend the meeting to talk about the advantages and disadvantages of the tax break. They have also asked representatives of Kennebec Valley Gas Co., which is proposing to build the $85 million gas line from Richmond to Madison and has requested the tax break from the dozen affected communities, to discuss the project in detail.

Residents overwhelmingly rejected the tax break by a show of hands at a special town meeting held Dec. 10. About 100 people showed up for the meeting at Hall-Dale High School.

Many residents coordinated efforts and campaigned to vote down the tax break proposal.

In February, the Board of Selectmen — over the strong objections of critics — voted to bring the tax increment financing district for the project back before voters at a referendum ballot in June.

Under the tax break proposal, the company wants the town to return 80 percent of property taxes to them the first 10 years after the project has started, and 60 percent the next five years.

The Kennebec Valley Council of Governments has been working as the liaison between Kennebec Valley Gas Co. and the towns since March 2011, forming a subcommittee of town representatives to work on the proposal.