SpaceX, the company that builds spy satellites for the Pentagon, had investors with ties to Chinese military contractors quietly holding stakes. That’s the kind of detail that tends to make national security officials lose sleep.

A private investor list obtained by ProPublica reveals that a businessman connected to Chinese military contractors was among overseas investors who acquired positions in SpaceX while it was still private. An entity linked to the Qatari royal family also took a stake. Now, as SpaceX prepares for what could be the largest IPO in history, targeting roughly $75 billion, the company has drawn a hard line: no mainland Chinese or Hong Kong investors allowed.

The quiet money trail

The ProPublica investigation sheds light on a problem SpaceX apparently knew about but didn’t exactly advertise. More than a dozen investors connected to Chinese or Hong Kong addresses were involved with the company in the past, according to the reporting.

One investor reportedly testified about facilitating Chinese investments while noting that SpaceX preferred to avoid direct exposure to China because of its defense contractor status. Chinese investors have historically routed money through offshore entities and intermediary structures, making the actual source of capital harder to trace.