Robert F Kennedy Jr's sister claimed he once released a snake into a swimming pool filled with children at a family birthday party.

The Health and Human Services Secretary, 72, has a history of bizarre interactions with animals, and recently made headlines for sharing a video of himself wrangling two snakes bare-handed on Dr Oz's patio.

On Monday, his sister, Kerry Kennedy, 66, told CNN's Erin Burnett that he once captured a snake at her daughter's birthday party, then threw it into a swimming pool filled with kids.

She recalled finding the snake in the garden during the party, so she called her brother, who came over carrying a pillowcase and his then-infant son, Aidan.

'He grabbed this snake and stuffed it into the pillowcase while he was holding his infant son. So, that was a little scary,' Kerry said.

'And then he walked up to where the rest of the birthday party was, and he reached into the bag. And the snake was just chomping on his hand, and he pulled out the snake to show the kids.' 

That's when Kerry said the situation took a disturbing turn, and Kennedy allegedly fed a vole to the snake, then threw the snake into the pool.

'Then there was a vole, and he grabbed that with his hand, and he put it into the bag with the snake, which made all the kids scream because now they were afraid the snake would eat the vole,' she said.

'So then he shoved his hand back into the pillowcase and grabbed the snake, which chomped on him a few more times.

'There were tons of kids in the swimming pool, and he released this snake that had chomped on his hand into the swimming pool.'

Kerry, who has been critical of her brother's role as Health and Human Services Secretary, said the anecdote shows he is unfit for the position.  

'This is somebody who, on the one hand, has a fascination with nature, but on the other hand has, you know, a lack of judgment when it comes to the safety and care of children,' she said.

'Is this the person who you want running HHS who's got this lack of judgment when it comes to health and safety?' 

The Daily Mail contacted Kennedy's office for comment. 

Kennedy has a long history of outlandish behavior with wild animals and has posted numerous photos and videos over the years of himself interacting with the creatures.

In May, he shared a video of himself catching two snakes with his bare hands while his wife, actress Cheryl Hines, squealed as she watched on. 

The video showed Kennedy, in suit pants and a tie, chasing two black snakes before snatching them up with his bare hands. 

Dr Oz can be heard saying: 'They're having sex!'

Kennedy sarcastically told his audience that the snakes were moccasins, more commonly known as cottonmouths, to which his wife yelled: 'Those are dangerous!'

He added that the snakes were biting him as Hines continued to beg her husband to release the writhing reptiles.

'You are nuts!' she continued, adding, 'Honey, honey, let it go. I can't watch. Bobby, please. Bobby, please!'

Dr Oz was heard laughing in the background as Hines grew increasingly distraught. Kennedy appeared unbothered by his wife's concern and laughed as the snakes tried to bite him. Black racer snakes are not venomous.  

During his presidential campaign in 2024, Kennedy acknowledged that he had left a dead bear cub in Central Park ten years earlier.

According to another story from his daughter Kick, Kennedy brought home the head of a whale carcass while they were vacationing in Cape Cod, the Kennedys' longtime go-to summer destination. He allegedly cut the head off with a chainsaw and strapped it to the roof of the family's car. 

And according to a recently published biography, Kennedy confessed in a diary entry that he once cut the genitals off a raccoon carcass he found on the side of the road so he could 'study them.'