Bill Maher of Maywood, N.J., traveled with Moore to seek health treatment in Cuba, where universal healthcare is in place, The New Jersey Star-Ledger reported Sunday.
Maher -- who has suffered more than five years with health problems brought on from his volunteer work at Ground Zero -- said he was not aware he was breaking any laws by visiting Cuba.
His medical treatment is depicted in Moore's new documentary, "Sicko."
Maher reportedly learned last week that he faces charges for violating travel restrictions. He and two other Ground Zero volunteers featured in the documentary are under investigation by the Treasury Department.
Maher told the Star-Ledger he thinks the government is pursuing them for political purposes.
"The reason they have a bug up their butt is about Michael," said Maher. "It's ridiculous. What about paying attention to the (Sept. 11) responders who are dying, who can't get any help? If we wind up going to jail, it's going to send another message out. Instead of helping (sick Ground Zero volunteers), they're locking them up."