Police have long had concerns about the sheer volume of partiers using ectasy at B.C. Lower Mainland raves. But what's disguised as ectasy often contains another, very ugly drug - crystal meth.

It is often consumed at raves like the one in Chilliwack, B.C., which attracted 5,000 party goers, from all over British Columbia and parts of Alberta and Washington State.

The Chilliwack crowd found themselves dancing in the company of plain clothed police officers, who seized pot, cocaine and a veterinarian drug called "special K."

The drug that is found the most is ecstacy.

It is why ectasy is known as the party drug. It's cheap and easy to get. Users are looking for a short party high.

But few of the Chilliwack partiers seemed to know dealers are cutting the ecstasy with crystal meth, a highly addictive drug that can bring on psychosis, and is cheaper for the dealers to make.

For information on the effects of Crystal Meth, check the Photo Gallery.

Sgt. Scott Rintoul of the RCMP Drug section says he has been monitoring ecstacy trends for the past eight years.

He said over 70 per cent of the stuff he seizes at events like the Chilliwack rave contain crystal meth.

A Health Canada analysis of some of the ecstacy pills that were seized from one of the Chilliwack partiers revealed exactly what the RCMP had been expecting.

Seventy per cent of the tablets analyzed contained methamphetamine, an unpredictable drug with often devastating consequences.

"[It's] extremely addictive, extremely dangerous,'' said Rintoul.

"Family members don't recognize their family member that has been a meth user two or three years later," he said.

Rintoul believes more than two-thirds of users at a rave are taking ecstasy.

But for some of the young party-goers who attended the Chilliwack bash, knowing it often contains meth doesn't seem to worry them.

One of them popped three ecstasy tables before he even got there.

With a report by CTV British Columbia's Michele Brunoro.