The `Twilight Saga` actor is planning to step up his security after being bombarded by saucy mail from female admirers and came up with the idea of a decoy after one of his more dedicated fans started following him and girlfriend Kristen Stewart everywhere.
A source told the Daily Star newspaper: "He`s become the focus of a group of over-zealous female fans.
"Robert is constantly inundated with fan mail but one group of four girls have been targeting him repeatedly, telling him they want to do ruse, saucy things to him. One girl from Japan has started turning up wherever he is.
"Robert thinks there`s only one thing for it and that is to increase his security and use a bodydouble. It may seem a bit extreme but at least he can now be in two countries at once and spend some quality time with Kristen."
It was previously revealed that Robert needed 25 security guards to protect him when he was shooting his role as vampire Edward Cullen in the `Twilight Saga` movie franchise.
The British star said earlier this year: "They had to hire another ten security guards and they had to form a ring around you and it had to be every single day. And if you`re doing a movie for $1 million or $2 million, security is expensive. So you hire 25 security guards for one cast member. "The whole thing got over-run and people are grabbing you and that`s just you on the way from set to trailer."
Robert, 24, has previously admitted his legions of fans and the pressure of fame made him "really paranoid".
He explained: "I was getting really paranoid. But then I realised that if tomorrow I say, `OK, I`ve had enough we`re stopping everything,` it won`t change anything.
"Might as well try to accept it and stay Zen as I have no control over it. It`s not always easy. But whining won`t change anything."