In yet another chapter in the political struggle over Harvard’s attempt to purchase 90 acres of industrial Boston land, an environmental review agency informed the would-be seller last week that they intend to review the sale and could even stop it completely.

Two weeks ago, Harvard bid $75 million to buy the land—an industrial plot crossed by railroads and cut by the Turnpike—from its current owner, the Massachusetts Turnpike Authority, which is low on funds after pouring billions into the Big Dig.

The parcel, known as Allston Landing South, has been the subject of political wrangling for months, including recent protests from a slew of powerful politicians, who say they are concerned that Harvard would push the rail yard—which some say is crucial to the local economy—off of the land.

But two weeks ago, the Turnpike Authority authorized their chair to approve Harvard’s bid. Pending all of the paperwork, the deal seemed a sure thing.

But late last week, the state’s Executive Office of Environmental Affairs (EOEA) instructed the Turnpike to prepare for an environmental review of the land, which could potentially derail the deal completely, according to Katie Cahill, an EOEA spokesperson.

“Basically we would need to be assured that the [railway] link will be kept operational for as long as the state needs it to be,” Cahill said of the EOEA’s review process.

The EOEA warning follows closely on the heels of outcries from prominent political officials, including Boston Mayor Thomas M. Menino and the state transportation secretary.

Many have said that the parcel’s tracks—owned by the CSX Company—play a crucial role in freight transportation as the only major rail yard near Boston’s port.

EOEA spokesperson Cahill said that her agency needed evidence that the rail yard would remain as a crucial part of Boston’s port system.

The loss of the rail yard could also affect untold environmental impact in the surrounding area, she added.

“[If the yard is evicted] the stuff that comes into the port will have to be trucked out to Worcester [the next nearest rail yard], which causes its own traffic and pollution problems.”

The EOEA sent a letter to the Turnpike Authority late last week, requesting documentation on how Harvard could change the land if they owned it.

If the agency decides that the sale could cripple the railway at anytime in the future, the deal could be halted entirely, Cahill said.

Turnpike Board Chair Matthew Amorello, who received the EOEA’s letter on Friday, said he was unsure about how the review could impact the deal, and could not confirm that the Turnpike’s land transfers were lawfully subject to EOEA approval.

“I just looked at it and we sent it to the legal department,” said Amorello. “I don’t know what it means.”