Robert F. Kennedy Jr once pulled over on a highway to cut the penis off a dead raccoon so he could “study it later”, according to a new biography of the US health secretary.

The bizarre account described in RFK Jr: The Fall and Rise, by Isabel Vincent, a New York Post journalist, is included in diaries allegedly written by the US’s top civilian health official.

“I was standing in front of my parked car on I-684 cutting the penis out of a road-killed raccoon, thinking about how weird some of my family members have turned out to be,” Mr Kennedy reportedly wrote in 2001.

“My kids waited patiently in the car,” the entry added.

Mr Kennedy then took the raccoon’s organs to “study them later”, Ms Vincent told People magazine.

“You have to understand, Bobby wanted to be a veterinarian as a kid. His after-school job was at the National Zoo in Washington, DC,” Ms Vincent said.

“So he’s got a great love and interest in animals and a freezer full of roadkill, I’m sure, where he studies it.”

The allegations are the latest in a series of troubling interactions between Mr Kennedy and dead animals.

He admitted in 2024 to dumping a dead bear in Central Park a decade earlier, staging the scene to make it look as though the animal had been hit by a bicycle after spotting that it had been killed by another driver in the Hudson Valley.

“I pulled over and I picked up the bear and put him in the back of my van because I was going to skin the bear,” he said in the clip. “It was very good condition and I was going to put the meat in my refrigerator.”

“I’ve been picking up roadkill my whole life,” he told reporters in 2024. “I have a freezer full of it.”