Critics slam “Breaking Bad” for being involved in an uber-sketchy cancer charity!

Fans of the AMC hit about a high school teacher battling cancer have donated a whopping $125,000 to a nonprofit organization promot­ed on the show’s website.

But an exclusive ENQUIRER investigation has discovered that the charity, the National Cancer Coalition, is being blasted for fi­nancial shenanigans by a top watchdog group.

CHARITYWATCH, an organization that rates the performance of U.S. charities, gave the NCC a shocking “F” based on its dodgy fundraising and spending practices.

“They flunk our standards,” CharityWatch president Daniel Borochoff told The ENQUIRER.

“This is not a group that you want to contribute to.”

“Breaking Bad” got tangled up in the char­ity brouhaha after the TV son of lead char­acter Walter White, a meth-dealing chemis­try teacher played by Bryan Cranston, created the web­site “Save Walter White” to raise money for his medical expenses.

AMC posted the fictional website on “Breaking Bad’s” official website during the show’s second season as a spoof. But fans responded with an outpouring of real cash, which went to the NCC. Unfortunately, a lion’s share of the money raised by the NCC goes to administrative costs, according to CharityWatch.

The watchdog group believes that charities should spend no more than 35 percent of their budget to raise money. But they say the NCC spends 70 to 84 percent of their donations on fundraising!

NCC president Robert Landry defended the group, pointing out that it solicits donations of FDA-approved medications and medical technology.

But CharityWatch isn’t buying that explanation.

“The NCC purchases goods for a minimal amount of money, inflates the value and calls it a ‘contribu­tion,’ ” claimed Borochoff.

“My term for that is FMV – Fake Made-up Values.”

Meanwhile, an AMC spokesman distanced the network from the NCC, telling The ENQUIRER: “That site is not something we actively promote.”