This is the chilling moment a Thai man followed a young backpacker up a mountainside - moments before beating her to death with a rock.

While high on meth, Ronnakorn Romruen, 24, stopped Miriam Beelte, 26, and asked her for sex while she was riding a rented motorcycle on Koh Si Chang, Thailand, on Sunday (April 7).

But when she refused he followed her to a secluded ancient stone palace where she parked the bike, unaware the killer was stalking her.

CCTV footage shows Miriam in a blue dress and black flip-flops as she walks up the long stone path to the top of the hill.

Romruen, wearing a black top and army camouflage trousers, follows behind moments later with a ring of marigolds in his hand.

He then pounced on Beelte and raped her on the steps leading up to the Phra Chulachomkla stone palace monument.

Having attacked the young woman from Hildesheim, Germany, he then battered her to death with a rock to prevent her from contacting police.

CCTV of the haunting last moments emerged today as Romruen was taken back to the area for a crime re-enactment flanked by police.

Pictured with a blue bag over his head, Romruen was in handcuffs as he again showed police how he murdered the woman.

This is the chilling moment a Thai man followed a young backpacker up a mountainside - moments before beating her to death with a rock.

Meth-crazed Ronnakorn Romruen, 24, stopped Miriam Beelte, 26, and asked her for sex while she was riding a rented motorcycle on Koh Si Chang, Thailand, on April 7.

But when she refused he followed her to a secluded ancient stone palace where she parked the bike, unaware the killer was stalking her.

CCTV footage shows Miriam in a blue dress and black flip-flops as she walks up the long stone path to the top of the hill.

Ronnakorn, wearing a black top and army camouflage trousers, follows behind moments later with a ring of marigolds in his hand.

He then pounced on Miriam and raped her on the steps leading up to the Phra Chulachomkla stone palace monument.

Having attacked the young woman from Hildesheim, Germany, he then battered her to death with a rock to prevent her from contacting police.

CCTV of the haunting last moments emerged today as Ronnakorn was taken back to the area for a crime re-enactment flanked by police.

Pictured with a blue bag over his head, Romruen was in handcuffs as he again showed police how he murdered the woman.