Tesla Inc. is being sued for more than $2 billion by electric-hydrogen truck startup Nikola Motor Co., which is claiming its patents were infringed.

In a lawsuit filed Tuesday in Arizona, Nikola claims Tesla TSLA, +1.53%   copied the design of its big rigs, which Nikola first unveiled in May 2016.

According to a court filing, in early November 2017, Nikola sent a cease-and-desist letter to Tesla pointing out features on the electric Tesla Semi that resembled features on its own semi trucks — including the wraparound windshield, mid-entry door and aerodynamic fuselage — and demanded Tesla delay the public unveiling of the Semi until the infringement issues were settled. Tesla did not respond, the filing said, and Elon Musk unveiled the truck at an event in Hawthorne, Calif., on Nov. 16.