Photo of Model X courtesy of Tesla Motors.

Photo of Model X courtesy of Tesla Motors.

Tesla Motors has completed both "alpha" and "beta" prototypes of the Model X battery-electric SUV, the company noted in its annual proxy filing with the U.S. Securities and Exchange Commission (SEC).

When developing new vehicles, Tesla produces alpha and beta prototypes before completing a production-ready version. Production of the Model X is still expected to begin in late 2015.

Tesla also noted in its recent SEC filing that it still has not completed the alpha prototype of the Model 3, the company’s lower-priced electric vehicle. Tesla plans to unveil the Model 3 in 2016 and put it on sale by 2017. The vehicle is expected to retail for $35,000.

Click here for Tesla’s SEC filing.