Former head of Nikola Trevor Milton accused of sexual assault

Sexual assault allegations against the founder and former chairman of Nikola prompted additional questions Tuesday about the electric truck startup and its pending deal with General Motors.

The allegations by two women concern Trevor Milton, who abruptly resigned September 21 amid accusations of fraud that had led to a big pullback in shares following the September 8 GM announcement.

Milton denied the charges through a spokesperson.

Craig Johnson, a Utah attorney representing the two women, said he was in contact with law enforcement authorities over complaints of unwanted sexual contact when they were minors.

Aubrey Smith, Milton's cousin, alleges that in 1999 when she was 15 years old, Milton "groped her breast without her consent," according to a press release from Johnson's firm.

The second victim, who is unnamed, alleges that in 2004 when she was 15, Milton "digitally penetrated her vagina with his finger after work one day," according to the press release.

Milton "strongly denies these false allegations," a spokesman said. "At no point in his life has Mr. Milton ever engaged in any inappropriate physical contact with anyone."

Shares of Nikola plunged 8.6 percent to $17.64.

The company's share price had been under pressure for the last three weeks following a report by Hindenburg Research that called the company an "intricate fraud."

The report was released a few days after GM announced a manufacturing partnership with Nikola that would give the auto giant an 11 percent stake in the startup.

GM, which had previously reaffirmed plans to complete the deal, hinted Tuesday it might change course.

"Our transaction with Nikola has not closed," GM said. "We are continuing our discussions with Nikola and will provide further updates when appropriate or required."