His independent White House campaign has fizzled, but the flow of bizarre stories of Robert F Kennedy Jr’s unorthodox handling of the carcasses of wild mammals has experienced no similar suspension. An environmental group is calling for a federal investigation into the former presidential candidate for an episode in which he allegedly severed the head of a washed-up whale with a chainsaw – and drove home with it strapped to his car’s roof. The episode has parallels with another extraordinary tale reported earlier in August in which Kennedy confessed to dumping a dead bear cub in New York’s Central Park and attempted to make it look like the animal was killed by a bicyclist. The latest grisly revelation, about the whale head, is not particularly new – it stems from a 2012 interview Kennedy’s daughter Kick gave to Town & Country magazine, in which she talks about a visit to other family members of the political dynasty in Hyannis Port, Massachusetts, more than two decades prior. But the story’s re-emergence, following the bear tale and other off-the-wall declarations – including claims that part of RFK Jr’s brain was eaten by worms and that he had an apparent fondness for barbecued dog – has angered activists at the Center for Biological Diversity Action Fund. The group previously denounced Kennedy’s candidacy and endorsed Democratic nominee Kamala Harris for president. In a letter to the National Oceanic and Atmospheric Administration (Noaa) this week, Brett Hartl, the organization’s government affairs director and chief political strategist, demanded an inquiry. “Mr Kennedy’s apparent transport of the marine mammal skull from Massachusetts to New York, and therefore across state lines, also represented a felony violation of the Lacey Act, one of the earliest wildlife conservation laws enacted by [the] United States in 1900,” he wrote, adding that it was also illegal to possess part of any animal protected by the endangered species act. “Normally, an unverified anecdote would not provide sufficient evidence as the basis for conducting an investigation. The [bear] story made it seem like this was normal behavior for him, so he may also possess additional illegally collected wildlife parts.” The former Kennedy campaign’s press office did not respond to a request for comment. And Noaa has yet to publicly acknowledge receipt of Hartl’s letter. The somewhat unpleasant recounting by Kick Kennedy – granddaughter of Robert F Kennedy, the assassinated former US attorney general and Kennedy Jr’s father – remains the only documented account of the whale incident. Describing her father’s fascination with animal skulls and skeletons as “eccentric environmentalism”, she tells how the whale washed up on a beach near Hyannis Port and he sped to the scene. “[He] ran down to the beach with a chainsaw, cut off the whale’s head and then bungee-corded it to the roof of the family minivan for the five-hour haul back to Mount Kisco, New York,” she said. “Every time we accelerated on the highway, whale juice would pour into the windows of the car, and it was the rankest thing on the planet. We all had plastic bags over our heads with mouth holes cut out, and people on the highway were giving us the finger, but that was just normal day to day stuff for us.” Hartl, on X, called RFK Jr an “environmental criminal”. In his group’s denouncement of his candidacy, it said “his conspiracy theories go against the science-based foundation of all environmental protections”, and that he was no different from Donald Trump in terms of policy priorities “driven by what will benefit Big Oil and the greedy corporations that fund them”. Kennedy announced he was suspending his presidential campaign last Friday and immediately endorsed Trump.