A relative of mine has recently arrived to the US on a B1/B2 visa, which normally prohibits any kind of work in the US. They’ve signed up for a COVID-related trial and have been accepted. Said trial offers a small (few hundred dollars) compensation for participating, which would be a nice bonus in addition to helping the medical community. The trial organizers do not care about the participants visa status, as long as you can report back a couple of times in the future.
Is it legal for someone on a B1/B2 to receive money for participating in a medical trial? Or should my relative participate while refusing payment?