According to The Local, the pair are thought to have been waiting for a connecting flight on their way back from Peru when customs officials at Schipol airport noticed the spiders during a routine baggage scan.
When they opened the suspicious-looking case, 200 live tarantulas - along with grasshoppers, millipedes and beetles, which the couple had put into little boxes - began to escape.
The Dutch finance ministry, which is responsible for the airport's customs system, confirmed that all the animals had been successfully captured and confiscated.
As the budding naturalists had taken the insects and arachnids from the wild, the creatures were then forwarded to the relevant authorities for inspection in case any of them were harbouring disease.
At this stage, it is not known what the couple had planned to do with their exotic acquisitions. A spokeswoman for the finance ministry added that Amsterdam customs officials had never encountered a collection of that size and kind before.