The US securities regulator has issued fines against a space transportation start-up and a special purpose acquisition vehicle for misleading investors in the first crackdown of its kind.

The Securities and Exchange Commission charged Momentus and its former chief executive Mikhail Kokorich for misleading investors about the company’s technology and the national security risks associated with its Russian founder.

Stable Road Acquisition, the Spac that last year agreed a deal to take Momentus public, was also charged along with its sponsor company, SRC-NI Holdings, and its chief executive Brian Kabot.

All parties other than Kokorich settled the civil charges and agreed to pay more than $8m in total penalties, the SEC said. The regulator has sued Kokorich personally, alleging fraud, in the US district court for the District of Columbia.

Anita Bandy, associate director of the SEC’s enforcement division, said: “Momentus’s former CEO is alleged to have engaged in fraud by misrepresenting the viability of the company’s technology and his status as a national security threat.”

The wide-ranging charges could herald a broader crackdown on Spacs, which have raised more than $100bn in the past year and helped launch companies on to public markets without a traditional listing process.

“This case illustrates risks inherent to Spac transactions, as those who stand to earn significant profits from a Spac merger may conduct inadequate due diligence and mislead investors,” said Gary Gensler, SEC chair, in a statement.

Momentus and Stable Road announced a proposed $1.2bn merger in October, which the two parties billed as creating the first publicly traded “space infrastructure company”.

Later, Momentus said in filings that it received a subpoena from the SEC in January for documents related to the deal. Last month, the company said it resolved a separate review by the Committee on Foreign Investment in the US into ownership interests previously held by Kokorich.

The SEC charged that Kokorich and Momentus had told investors that they had “successfully tested” the company’s technology in space, when in fact the only test had “failed to achieve its primary mission objectives or demonstrate the technology’s commercial viability”.

The agency also charged that both parties misrepresented the risk of national security concerns to the company’s business, while Stable Road repeated the misleading statements in public filings and “failed its due diligence obligations to investors”.

SEC officials highlighted the risks for Spacs that failed to do adequate due diligence on their targets, particularly with sponsors running out of time to strike deals within a two-year limit.

“One party’s lies do not absolve the other party’s responsibility to exercise due diligence,” an official said.

The deal between Momentus and Stable Road, which was revised as recently as last month, could still go ahead despite the charges. The companies have agreed to provide investors in the private investment in public equity, known as a Pipe, with termination rights that will allow them to redeem their investment should they wished to do so.

Spac investors will have the opportunity to see what Pipe investors choose before they vote on the deal, and the sponsor has agreed to forfeit 250,000 founder shares.

Momentus said: “Momentus and the Securities Exchange Commission have agreed on a settlement. We’re pleased to be closing this chapter and moving forward.”

Kokorich declined to comment. Stable Road and Kabot did not immediately respond to a request for comment.