WATCH: Men Claim Mailman Won't Deliver Because They're Gay

A same-sex couple in Detroit have asked their local post office to investigate why they aren't receiving mail -- they believe it's because the mailman learned they are gay.

James Lawson and his husband, Theodore Washington, say they are the only family living on Prevost Street, on the city's west side, which was previously littered with garbage, stripped cars, and old tires. But even after the couple got help from the mayor's office to clean up their block, they still haven't received mail in three weeks, the couple told Detroit TV station WJBK.

Even after moving the tires that blocked one entrance to the street for two weeks -- placed there to discourage illegal dumping -- the couple still never received their mail, they say. That's when they suspected a more sinister explanation for their empty mailbox.

"[The mailman] has made comments to the neighbor about 'the faggots can go get their mail from the post office,'" Lawson said.

The couple told reporters they received a notice from the local post office informing them that their mail delivery had been canceled indefinitely -- but that's not a workable option for Lawson, who has cancer and receives medications and doctor's notices through the U.S. Postal Service.

"I'm not getting my medications, I'm missing doctor's appointments, government appointments, and it's frustrating," Lawson said.

Despite the postal service's notice, which cites the tires blocking entry on one side of the street as the reason the mail carrier can't access their home through his regular route, both men noted that medical vehicles and dump trucks have no problem getting to the home through the other side of the street.

When the couple reached out to the postal service, they were told to move, they say.

"Just move" was the local post office's response, Washington said. "'Just take yourself and your life and your family elsewhere.' When we're trying to make it our home and our community here."

The postal service is launching an investigation into the allegations, a representative told WJBK, noting that such antigay behavior, if proven, "will not be tolerated."

Watch WJBK's report below.