In a move that could bring the big development project to a temporary halt, the San Francisco Business Times reports that the developers of the massive project at 16th and Mission Streets, Maximus Real Estate Partners, are suing the owner of the property, the Jang family, for breaking their 2013 sale agreement.

The lawsuit accuses the Jangs of allegedly intentionally slowing down the project and entering into negotiations with other potential buyers.

The Business Times reports that the other buyer is an unnamed real estate developer from the East Coast who allegedly offered to pay $13 million more than Maximus offered for the site, for a total of about $55 million. Maximus, it alleges in the suit, has already spent around $12 million on the project.

The site is already at the center of controversy, drawing extensive opposition at meetings and presentations, where protesters have rallied for more affordable homes in the roughly 300-unit building Maximus has planned.

Read the full story here.

Update: Joe Arellano, who handles communications for the 16th and Mission project, has sent a statement about the lawsuit.

“We are hopeful that a mutually agreeable resolution can be reached. In the meantime, we remain fully committed to the development of 1979 Mission. It’s our strong belief that the proposed project will provide new, well-designed, market-rate, middle-class and affordable workforce housing that will help alleviate the city’s housing shortage – and that is the right thing to do.”