A surgeon in the U.S. has been taking excess body fat from liposuction patients and using it to help power his car.

Dr. Craig Alan Bittner confessed he had used fat from his patients in order to power his vehicle. According to California state health officials, this practice is not legal.

The surgeon wrote on his Web site, which is no longer online, that most of his patients asked him to use their fat resulted after liposuction, for fuel “and I have more fat than I can use.” Besides, he added that this way he could actually save the Earth. “Not only do they get to lose their love handles or chubby belly but they get to take part in saving the Earth," Bittner said.

Doctor’s illicit activities came to light after some former patients filed lawsuits against him, saying that he let his unlicensed girlfriend together with one of his assistants to perform surgical procedures which resulted in patients being disfigured, said Andrew Besser, lawyer for three of these ex-patients.

The California public health department is performing an investigation into the case. The authorities believe that one gallon of gas equals to one gallon of fat in terms of having the power to run cars.

Bittner wrote on his former Web site that he performed an estimated 7,000 liposuction operations, adding that a gallon of human fat will produce about the same amount of biofuel.