Leonardo DiCaprio refuses to use deodorant.

The 37-year-old actor has reportedly upset girlfriend Erin Heatherton with his poor personal hygiene, which is down to his fears for the environment and passion for conservation.

A source explained: "Leo has let his love for the environment take over his whole world and it's killing his love life.

"He only showers a couple of days a week to conserve water and he considers deodorant to be unnatural.

"Erin loves him dearly but is starting to feel like Leo loves the environment more than her."

Leonardo is said to be an "avid" recycler, but regularly misses the pick up days, leaving his kitchen with a foul odour from the rubbish left behind.

The source added to National Enquirer magazine: "Erin has warned him to clean up his act and his hygiene. If not, he may wind up chasing off the woman of his dreams."

Leonardo isn't the only star to have been criticised for their poor personal hygiene.

It has previously been claimed that Robert Pattinson rarely showers and has upset cast and crew on the 'Twilight Saga' with his pungent body odour.

A source close to the star - who plays vampire Edward Cullen in the film franchise - previously said: "He stinks. I mean, it's awful. He never showers, and it drives people on the set crazy. He completely reeks."