PRINCESS DI’s secret lover HASNAT KHAN erupts in fury! For the love of all that is holy WHY?!   

 In the summer of 1995, stunning Princess Diana was swept off her feet by Pakistani-born heart sur­geon Dr. Hasnat Khan.

But now the former hunk has packed on the pounds since then.

It’s a far cry from the dashing doc that Diana called “Mr. Wonderful.” She was so smitten by Khan that she once turned up at his hospital completely naked except for a long fur coat, according to royal biogra­pher Nicholas Davies.

Diana flipped for Khan while visiting a heart patient friend at London’s Royal Brompton Hospital.

Author Kate Snell says Diana called Khan “drop-dead gorgeous” and gushed that their meeting was “kar­mic.” But the forbidden relationship was destined to fizzle because Khan believed the public attention would be unbearable and, besides that, his family disapproved of Diana because she was not Muslim.

“She wanted to marry him,” says Diana’s close friend Rosa Monckton, adding that Khan loved Diana too. “What he couldn’t cope with was the Princess of Wales…and all the baggage that she brought with her.”

Khan, 54, is working as a cardiology consultant at a London hospital, also has problems with the new movie “Diana.”

Starring Naomi Watts as the princess and “Lost” star Naveen Andrews as Khan, the film chronicles their two-year romance. But producers’ efforts to gain the doctor’s support fell on deaf ears.

“I have never given my approval for it,” said Khan, who is single after an arranged marriage ended in divorce. He also blasted the film as “completely wrong” and based on “cruel lies.”