Robert F. Kennedy Jr. Reacts When Quizzed Over Chopped Raccoon Penis, on Video

RFK Jr.’s keeping a tight, trash-can lid on his dead raccoon penis saga -- ’cause when TMZ DC went digging, his reaction was straight dumpster gold!

Check the clip -- TMZ put Trump’s Health and Human Services chief on the spot Thursday with the question no one else would touch ... what happened to that raccoon penis, and where’s it at now? RFK Jr.’s answer? Radio silence ... followed by a laugh doing all the talking.

You gotta see the video -- 'cause that wasn’t just any laugh ... it was a tail-end-of-the-truth kinda laugh ... like there’s a whole extra layer to this chopped-up critter story he’s keeping buried.

In his new biography "RFK Jr.: The Fall and Rise," he admits when he stumbled on the roadkill ... he took matters into his own hands -- literally -- chopping off the animal’s bits for further study.