Canada Border Services Agency data analyzed by CBC News shows China was the largest single source of drugs seized between 2007 and 2012, most of it in the form of substances often referred to as date rape drugs.

The bulk of the $1.5 billion total of drugs seized from China was from a single bust in Montreal in 2009 that intercepted a shipment of GHB, known commonly as a date rape drug, valued at $1.4 billion.

Ketamine, another hallucinogen often used as a date rape drug, also figures prominently in drug busts from China, according to analysis by CBC News Network's Power & Politics of CBSA data obtained through the Access to Information Act.

Although the number of seizures of drugs from China — 1,879 over the six years — is lower than some other countries, China is becoming a real concern, said the RCMP's Ken Cornell, who heads one of the force’s anti-drug smuggling divisions.

Top 5 drug sources Number of seizures and total value, 2007-12: China: 1,879, $1.5B.

Germany: 348, $1.4B.

U.S.: 12,330, $539.4M.

Pakistan: 1,160, $437.7M.

Unknown: 13,337, $277.3M. Source: CBC News analysis of CBSA data

It is one of the reasons the RCMP signed a memorandum of understanding with China in 2010 to share intelligence with an eye to combating smugglers.

But it has been a struggle.

"We have difficulty trying to share intelligence with the Chinese because it's difficult for them to do investigations when there are so many different [types of drugs]. They have a huge chemical and pharmaceutical industry in that country," Cornell said.

Cornell dislikes the term "date rape drug" used to describe GHB, ketamine and Rohypnol, stressing that they are used primarily as hallucinogens.

The drugs have made headlines because of the prominence they've played in sexual assaults, where the drug is slipped into a drink to knock a person out and make them an easy target for sexual assault.

Garry Clement, a former RCMP officer who heads up a company with an expertise in combating organized crime, said he believes a lot of drugs smuggled into Canada eventually wind up in the U.S.

Clement said what's also disturbing is the role of organized criminals. He said they tend to be the ones behind drug busts with street values ranging from the hundreds of thousands of dollars to millions, and in the China case, more than $1 billion.

Role of intelligence

GHB: Jaime's story "It's the most brutal thing I’ve ever experienced in my life because I didn’t know what happened to me," says Jaime, recalling the sexual assault by someone who had slipped him GHB, a date rape drug. The event happened at a bar several years ago. He remembers taking a drink, and then waking up and finding a man "on top of me." Jaime, using a pseudonym in order to remain anonymous, said he still struggles to maintain relationships with women, family and friends. Keeping a job is tough. The past is still too fresh to discuss openly. Still, he felt it was important to explain how devastating so-called date rape drugs like GHB, ketamine and Rohypnol can be, and why people need to be aware of what can happen. "I've tried to put this behind me ... so many people have tried to help in so many different kinds of ways, and it has never worked."

That GHB bust is believed to be the border service agency’s biggest. In the 2009 operation, officers seized 69 drums containing a "suspected illegal substance," which was "confirmed to be GHB," the CBSA said. The substance in the barrels did not contain 100 per cent GHB, though the agency declined to confirm the exact percentage.

Clement and Cornell said such large busts do not result from random searches, but rather from intelligence the CBSA and RCMP have gathered working with colleagues in the United States and overseas.

Cornell describes how information sharing leads to a bust.

"You will get a call from a customs official in Germany who says, 'We've got a shipment of furniture that we've done some testing on'… and they determine that they’ve got six kilos of heroin on board that came from Afghanistan or something like that," Cornell said.

"We'll have undercover operators who will pose as shipping companies, do the actual delivery and gather the evidence that we need to lay charges against these characters."

Intelligence is one of the areas affected as the border services agency reduces spending as part of the federal government’s bid to get rid of the deficit.

In the 2012 budget, the government announced the agency would lose 10 per cent of its budget. The union for the border guards said it expects that will mean the loss of 325 frontline officers, including 56 intelligence agents, and an overall cut of 1,350 positions.

In an email to CBC News Wednesday, the CBSA said it sent out 1,132 letters to employees last year saying their positions may be no longer required, but said the agency was not yet in a position to provide a final number of layoffs.

The agency said it will take "a risk-based approach and focus intelligence activities on priority areas" to maintain its ability to nab smugglers, while attempting to minimize the impact of cuts on frontline services for travellers and businesses.