US electric-truck maker Nikola Corporation on Sunday said that its founder Trevor Milton has stepped down as Executive Chairman, as it battles in allegations with a short-seller about misleading investors and automakers.

“The focus should be on the company and its world-changing mission, not me. So I made the difficult decision to approach the Board and volunteer to step aside as Executive Chairman,” said Milton.

Stephen Girsky, Former Vice-Chairman of General Motors Co and a board member of Nikola, have been named as the Chairman. 

Earlier this month in a report, short-seller Hindenburg Research alleged that Nikola Crop. Misled investors over its technology, sending shares of the company spinning lower. Hindenburg said that it had gathered enough evidence for showing false statements made by Milton about possessing proprietary technology and to a partnership with large automakers. 

Nikola rejected the accusation and threatened to take legal actions against Hindenburg.

Two days before the Hindenburg report, US vehicle manufacturer GM said it had taken an 11% stake in Nikola for about $2 billion and had agreed on a partnership to make electric pickup trucks to compete with rival Tesla Inc.