Chelsea Clinton underwent a series of secret plastic surgery procedures in a desperate attempt to hide the fact she is NOT Bill Clinton’s real daughter, a former top White House aide claims!

Best-selling author Roger Stone, who served as an advisor to President Richard Nixon, is blowing the lid off the 35-year cover-up in his blockbuster new book, “The Clintons’ War On Women.”

Stone claimed Chelsea was conceived during Hillary’s secret affair with disgraced Clinton crony Webster Hubbell (inset photo), a lawyer and once close Clinton family friend.

Hubbell served time for defrauding legal clients and evading taxes. He was also Hillary’s law partner at the prestigious Rose Law Firm in Little Rock, Ark., at the time of Chelsea’s birth.

“It’s important to know who Chelsea’s real father is because it proves the Clinton marriage is a dysfunctional sham,” Stone told The ENQUIRER.

“My co-author confronted Chelsea and asked her if Hillary had ever told her Webb Hubbell is her father. Chelsea said, ‘I’m proud to be the daughter of my parents.’

“That’s a non-answer! When a reporter reached Hubbell in his Arkansas office and asked if he was Chelsea’s father, Hubbell said, ‘No comment’ and hung up.

“Why won’t either one of them answer the question?“

In his explosive book, Stone wrote, “On Feb. 27, 1980, Chelsea Clinton was born. As she grew, she bore none of the distinct features of Bill … but curiously many facial similarities to Hubbell. The genetic giveaway is the protruding large lower lip that both Hubbell and Chelsea possess.”

And Stone told The ENQUIRER: “The resemblance between Chelsea and Webb Hubbell is uncanny. Chelsea underwent plastic surgery not to look better but to conceal Hubbell is her REAL dad!”

The ENQUIRER first raised the possibility Chelsea underwent plastic surgery back in 2004 — noting the “First Daughter has morphed from a plain Jane into stunning swan practically overnight, prompting intense speculation that she has gone under the knife.”

One insider said at the time: “Her face seems thinner, her chin more pronounced and her trademark chipmunk cheeks have practically disappeared. It seems all her features are perfectly proportioned.”

And a New Jersey plastic surgeon, who hadn’t treated Chelsea, but studied photos of her for The ENQUIRER in 2004, said: “Chelsea looks like she may have had her eyes lifted and the tip of her nose reduced.

“And she may have had a chin implant!”

Insiders insist she’s trying to look like Bill — and erase any resemblance to Hubbell!