Government inspectors have seized 3,500 fatbikes imported from China because they pose a risk to road safety and may not meet official standards for electric bicycles.

The chunky two-wheelers with wide tyres were being sold as as electric bikes for “extremely low prices”  but had the technical ability of a small moped, the inspectors said in a press statement. The decision to sequester the bikes was taken after consultations with the public prosecution department.

Mopeds require different certification, insurance and helmets and can only be used by the over-15s.

If a fatbike is capable of travelling at more than 25 kph then it is an “uncertified and uninsured moped”, compliance director Karin Visser said. “And if you realise that, would you still let your child use one, without insurance, driving licence, helmet and number plate?”

Fatbikes have soared in popularity since the government decided everyone using a moped should wear a helmet, leaving national and local officials undecided about how to deal with them.

They are also easy to soup up to travel at much faster speeds. More than half of fatbikes checked by police in Amsterdam in the last five months had been tinkered with to go faster than the maximum of 25kph.

Road safety experts are calling for a minimum age at which youngsters can use fatbikes following a surge in accidents.

Safety campaign group VeiligheidNL has told broadcaster NOS there should be a minimum age of 16 to use the bikes after doctors reported a “worrying” rise in the number of accidents involving young teenagers using the two-wheelers.

In 2022, just seven fatbike riders ended up in hospital emergency departments, but last year that had soared to 59. In the first four months of this year, there were 33 hospitalisations, a trend which if continued would take the full year total to around 100.