WHITNEY HOUSTON flunked a routine medical exam two weeks before she died in a tepid bathtub, say sources.

The desperate diva had sought a facelift to be performed by a Beverly Hills, Calif., plastic surgeon, RadarOnline.com reported.

But Dr. Marc Mani, a board certified plastic surgeon, refused to perform the procedure on Houston after she didn't pass the medical clearance exam that tests a patient's heart, lung and liver, according to a source.

"She was concerned about her appearance and wanted a facelift," the source said.

Dr. Mani refused to confirm to whether Houston, 48, who was found dead at the Beverly Hilton on Feb. 11, had attended his clinic, citing federal medical privacy laws.

Dr. Mani said he doesn’t “overindulge” celebrities by allowing elective surgeries to go ahead if they did not pass medical clearance.

“As a plastic surgeon who treats a lot of celebrities you have to be very strict about medical clearance,” Dr. Mani stated.

“Medical clearance includes a very thorough battery of tests including heart tests, lung tests, liver tests and other laboratory tests.

“In the years past, I have cancelled surgeries based on medical clearance both for celebrities and other patients. I feel very strongly about celebrities’ being overindulged by physicians, I treat a lot of them and care for them.”