There was a significant change in the drug market during 2010 according to the Guernsey Border Agency.
Overall drug seizures were down, but those involving controlled drugs and particularly class B drugs, including the former "legal highs", increased.
There were 56 seizures with a street value of £48,173 in 2010 compared to 32 valued at £3,129 the year before.
Rob Prow, agency chief, said: "Drug traffickers [and] money launderers have become more sophisticated."
Following the publication of the agency's annual report for 2010 he said the biggest challenge was maintaining its current vigilance while coming under increasing financial restraints.
Mr Prow said: "It is the type of work that does demand a lot of human resource, covert surveillance, issuing passports, collecting revenue - these are all done by people and very skilled and highly trained people at that.
"It is a real, real challenge. I can't think of one area of work we do that is diminished or has shrunk, it's all getting more and more demanding."
The agency employs a total of 93 staff and has been assigned a budget of just under £6m for 2011, which was down by more than £100,000 on its 2010 budget.
Mr Prow said: "We look at absolutely every area of what we do and try to be as efficient as we possibly can, our main costs are staff though.
"You need officers on the front line, you need officer working to intelligence, we're in the game of turning intelligence into hard evidence and it has to go through the scrutiny of the courts - we can't cut corners.
"One has to be realistic in times of financial restraint and I think the challenge really is to maintain where we are and perhaps improve and develop with the resources that we've got."