Back when I was a Grist underling intern, I wrote a piece about the world’s strangest biofuel sources, including, ahem, ass fat.

Now it appears that using that trunk junk to power your car is not only gag-worthy, but also illegal. Beverly Hills doctor Craig Alan Bittner is under investigation for using his patients’ flab to power his and his girlfriend’s SUVs:

Greenies like the fact that waste, such as coffee grounds and french-fry grease, can be turned into power. “The vast majority of my patients request that I use their fat for fuel — and I have more fat than I can use,” Bittner wrote on lipodiesel.com. “Not only do they get to lose their love handles or chubby belly but they get to take part in saving the Earth.” Bittner’s lipodiesel Web site is no longer online.

Using fat to fuel cars might be environmentally friendly, but it’s definitely illegal in California to use human medical waste to power vehicles, and Bittner is being investigated by the state’s public health department.

Although it’s unclear when Bittner started and stopped making fat fuel or how he made it, his activities came to light after recent lawsuits filed by patients that allege he allowed his assistant and his girlfriend to perform surgeries without a medical license.

Wired, however, thinks the whole thing is a fraud flabrication.