At least 30 road signs worth $10,000 have been vandalised or stolen in the Grey district in the past three weeks.

The Grey District Council notified police this morning after the latest discovery - a line of speed and directional signs from Greymouth as far as Blackball, Lake Brunner and Mitchells, either deliberately knocked over or removed - probably by a four-wheel-drive vehicle with bull-bars.

It follows the smashing down of give way signs at both ends of the Cobden Bridge last weekend in an act police said then would have been done by a show-off in front of late-night spectators.

Senior constable Mike Tinnelly, of Greymouth police, said council staff alerted police this morning after discovering the latest vandalism, which amounted to "a complete waste of taxpayers' money".


Police were investigating but meantime anyone with information which might lead to the culprit or culprits being identified would be appreciated, Mr Tinnelly said.

Council roading assistant Peter Detlaff said sign vandalism throughout the district had escalated lately.

The large 50km/h speed limit signs at Taylorville, each costing about $600, had gone missing this week, while give way signs were discovered missing near the Stillwater Bridge this morning.

Further out at Inchbonnie, a large chevron cluster of directional arrows had been knocked over and all the signs on the back road through Mitchells to Kumara were also missing.

"Some of them have broken posts, some of them have been knocked down. This seems to be have been going on for the past three weeks. We're probably talking 20 to 30 signs."

Mr Detlaff said the vehicle or vehicles involved in knocking over the signs in the Lake Brunner area would not have come off lightly as the council had used heavier posts than normal to counter the high winds in the area; some of those posts had been snapped off at ground level.

"By the marks, it looks like a four-wheel-drive with bull bars on it. There will be substantial damage to the bull-bars."

- Greymouth Star