The US Department of Justice sued Elon Musk’s SpaceX on Thursday saying the rocket company’s hiring practices discriminated against refugees.

The lawsuit alleges that SpaceX routinely discouraged asylees and refugees from applying and refused to hire or consider them, because of their citizenship status, in violation of the Immigration and Nationality Act (INA) from at least September 2018 to May 2022, the Justice Department said in a statement.

A SpaceX representative did not immediately respond to a request for comment.

“Our investigation also found that SpaceX recruiters and high-level officials took actions that actively discouraged asylees and refugees from seeking work opportunities at the company,” Assistant Attorney General Kristen Clarke of the Justice Department’s Civil Rights Division said in a statement.

US federal prosecutors are asking a court to award back pay and unspecified civil penalties for asylum seekers and refugees who it alleges were denied employment at SpaceX, according to the complaint filed with a Justice Department administrative judge in Washington.

Among its allegations, the Justice Department said SpaceX wrongly claimed in job postings under federal export control laws that it could only hire US citizens and green card holders. Such laws do not impose those hiring restrictions, the agency said.

Hawthorne, California-based SpaceX hired only US citizens and green card holders from September 2018 to September 2020, the agency said.

--With assistance from Loren Grush.

(Updates with new details throughout.)