Tesla Inc TSLA chairman Elon Musk has fueled his fiery rivalry with even more fuel Fisker Inc FSR chairman Henrik Fischer.

What happened: A new Teslarati report pointed out that DeLorean executives are being sued by Karma for pursuing a separate company. In response to the article shared on Twitter, Musk accused the Fisker CEO of doing the same thing to Tesla 15 years ago.

“How ironic, that’s what Henrik Fisker did to Tesla in 2007! Karma is a…” Musk said Wednesday via tweet.

Karma filed a lawsuit against DeLorean executives last month. The company claimed a group of former employees was asked to find investors to develop electric vehicles, but instead pursued outside ventures. Executives claimed they would be allowed to start a new company if necessary.

Why it matters: In 2007, Fisker was hired by Tesla to help design the Model S, but he left the EV company to design the Fisker Karma hybrid sports vehicle shortly after working with Tesla, per InsideEV’s.

Tesla broke away from Fisker’s job and started over when it learned that Fisker was starting a competing company. Tesla then proposed Fisker with a lawsuit, claiming he stole confidential information, but Fisker won the case in arbitration.

He then founded Fisker Automotive before filing for bankruptcy in 2013. The company’s assets were bought by Wanxiang Group in 2014 before being renamed Karma Automotive. Fisker’s design remains on the market today as the Karma GS-6.

Fifteen years after the lawsuit, tensions are still high. When Musk announced he wanted to buy Twitter Inc TWTR in a $44 billion dealFisker deleted his Twitter account and said he didn’t want his freedom of speech to be controlled by a competitor.

Fisker Inc, which was founded in 2016 and went public through SPAC in 2020, plans to start production of its flagship Ocean SUV in November.

Tesla delivered 254,695 vehicles in the company’s most recent quarter and expects to: a “very high volume” of vehicles vicinity…