Apple has poached five key engineers from A123 Systems to work in a new battery division at the Cupertino technology company, with some hires possibly going as far back as June, a new report claims. The battery maker claims that these hires violated agreements it had in place to prevent them from joining competing companies.

The employees the report refers to are Don Dafoe, Michael Erickson, Indrajeet Thorat, Mujeeb Ijaz, and Depeng Wang. Three of these workers—Erickson, Thorat, and Wang—were PhD project heads working on new battery technology. Ijaz headed up the System Venture Technologies Division, which oversaw work by all four of the others.

After these employees left the company, A123 has been unable to find leaders qualified to take over for them and their respective projects are essentially dead in the water. The company says it found emails on work computers between its former engineers and Apple’s talent acquisition staff, leading to the conclusion that the workers had been poached.

A123 Systems has filed a lawsuit against Apple and its former employees, saying that its former engineers breached their non-compete contracts, while claiming Apple had engaged in “unfair competition,” among other charges.

As noted in the image above (taken from the company’s home page), A123 Systems creates “advanced energy solutions” tailored toward, among other things, vehicles. It’s certainly an interesting development, given recent rumors that Apple is developing a car, and has poached Tesla employees to help with the project.