The tourists were "pushed" off the road by another motorist at roadworks near Klondyke Corner, a Tasman Police District Command Centre spokeswoman said.

A group of tourists were stranded for two hours after their keys were confiscated by a member of the public near Arthur's Pass on Saturday afternoon.

The group, understood to be Chinese nationals, were heading towards Christchurch to fly home after their last day in New Zealand.

The tourists were "pushed" off the road by another motorist at roadworks near Klondyke Corner, a Tasman Police District Command Centre spokeswoman said.

Police were alerted to the incident at 12.10pm.

"Somebody has stopped them, they were stopped at some roadworks.

"Someone has come up to them and taken their keys.

"They have taken their keys and handed them to some Coast to Coast people," the spokeswoman said.

The keys were taken about five kilometres down the road from the tourists to a group associated with the annual race.

The tourists were stranded without their keys for about two hours.

"Police officers have turned up and taken the keys [back to the tourists]," she said.

It appeared the person responsible for driving the tourist group was taking a break from driving on Saturday.

"There had been no complaints about them or their vehicle.

"They weren't aware that they were causing anyone any angst," the spokeswoman said.

Police could not confirm who alerted them to the incident, but were yet to talk to the person who took the keys.

The spokeswoman said there were other ways members of the public could alert police of possible dangerous drivers.

"There are mechanisms in place for notifying police instead of taking matters into their own hands."

For instance, motorists could dial *555, she said.