POLICE have been forced to hand back chemicals capable of being turned into an ecstasy-type drug to a Camberwell schoolgirl, after they discovered that it is not illegal for the girl to possess them.

Boroondara detectives confiscated the stash of chemicals and 1000 empty gel capsules last week after the mother of the 15-year-old found them in the girl's bedroom and called the police. The haul included 10 sealed bags of various chemicals - including hordenine, caffeine, phenylethylamine (or PEA) and phenibut - valued at $1000.

On internet forums, people who combined hordenine and PEA described the effects as ''super euphoria'' and ''a really evil high'', while others reported suffering a headache while coming down from the drugs and speculated that the combination could cause a stroke.

''When mixed properly, these make up a drug that has the same effect as ecstasy,'' Detective Senior Sergeant Daryl Cullen said. ''The caffeine is used to prolong the effect.''

Senior Sergeant Cullen said the schoolgirl had been given the cache by a 16-year-old boy, also from Camberwell, who had bought them on the internet. Police interviewed the youth, who was warned of the potential harmful effects of the chemicals and buying from unknown sources on the internet.