A getaway car's number plate, recorded in a scrawl by two French tourists after they were robbed and bashed, has so far failed to help police track down their attackers.

The hitch-hiking Frenchmen wrote down ZR9879 as the plate on the black four-door sedan being driven away by their two assailants in Bay of Plenty last weekend.

The attackers headed towards Rotorua on State Highway 2 after they robbed the French duo of nearly all their possessions, including their passports.

Detective Sergeant Darryl Brazier, of Mt Maunganui police, said the number plate written down by the victims was last registered three years ago to an Auckland address and to a car of a different description.


He said the list of suspect vehicles had grown to be in the hundreds, as police investigated similar plates to try to track down the offenders.

"The number plate given to us does not compute with the vehicle described by the victims. They have possibly gotten the registration number wrong," Mr Brazier said.

"The registration number they gave us has been expired for a number of years. (But) we can't rule out the number plate itself was stolen from the original vehicle and put on another vehicle."

The 21-year-old tourists were inundated with offers of accommodation, food and clothing after they complained of being attacked while hitch-hiking from Mt Maunganui to Rotorua.

Most of their gear was stolen, including passports, clothes, cellphones and a backpack.

Mr Brazier said several witnesses who saw the Frenchmen before they were picked up had contacted police with information.

He said police could not be sure where the attackers had driven to.

"This vehicle could be anywhere. All we know is we believe the vehicle, after the robbery, continued in the direction of Rotorua," Mr Brazier said.

"These two offenders have got to have told someone and they've got to be in possession of property that's clearly not theirs. We want to hear from anybody who knows where they are."

Mr Brazier said the tourists had continued on their holiday and were still keen to explore New Zealand.

"They're trying to put it (the attack) behind them," he said. "They understand that this is a one-off event that probably couldn't have been avoided other than not getting in the vehicle. They were in the wrong place at the wrong time."