When Queen Elizabeth II heard that Princess Diana had been involved in a serious car crash in Paris almost 18 years ago, she blurted out, “Someone must have greased the brakes,” a new biography says.

Princess Diana was killed Aug. 31, 1997, along with her boyfriend Dodi Fayed and their drunken driver when they crashed while being chased by paparazzi.

The Queen made the startling statement before she realized Diana had been killed, along with boyfriend Dodi Fayed, Ingrid Seward wrote in “The Queen’s Speech.”

“That astonishing remark reveals something of the extraordinary and complex relationship between her and Diana,” the royal biographer wrote in the Daily Mail.

The Queen’s reaction suggesting foul play followed years of strife between Prince Charles and his estranged wife.

At one point, Charles lashed out about Diana when his plans to take their sons to Sandringham were spoiled when he found out she had taken them to Windsor.

“Don’t you realize? She’s mad, mad and mad!” he shouted on the phone to his mother, Seward wrote.