Thieves are robbing long-distance coaches by sneaking dwarves into the luggage holds in sports bags.
Once inside, they slip out from their hiding places to rifle through the belongings of unsuspecting travellers.
Then they take their loot back to their hiding place and wait to be collected by another gang member when the coach reaches its destination, reports The Sun.
They have stolen thousands of pounds in cash, gems and other valuables in recent months.
Swebus, which ferries thousands of Brits across Sweden, has been among coach firms targeted.
A spokesman said: “We have had reports about several thefts by dwarves on the stretch between Vasteras and Stockholm.
“We’re thinking of installing video cameras.”
A Stockholm Police spokesman said: “We are looking at our records to identify criminals of limited stature.”