Macarthur police Senior Constable David Rook said a farm on the Macarthur Penshurst Road, about eight kilometres west of Macarthur, was targeted on Friday morning last week.

"It's a large sheep and cattle property owned by First Australian farmland.

"At 10am on Friday a motorist reported a large mob of sheep out on the Macarthur-Penshurst Road," Senior Constable Rook said.

"Workers attended and found that the property boundary fence had been cut into five-metre lengths in five different places along the Macarthur Penshurst Road.

"The damage is believed to have happened between 7.30am and 10am on Friday, in full view of passing traffic."

The police officer said all seven strands of wire on the fence were cut and the offender may have simply appeared to be someone working on the fence.

"We are appealing for witnesses or anyone with information about this incident to contact the Macarthur or Hamilton police stations or Crime Stoppers on 1800 333 000," he said.

"The sheep were out on the road on a bend where a truck recently overturned and it could have been catastrophic if a vehicle hit the sheep."

Senior Constable Rook said a nearby property, owned by the same company, was also targeted on Friday, along the Macarthur-Hawkesdale Road.

"Again that damage was caused in full view of passing traffic," he said.

" The fence was cut in two places, again into five metre lengths and we suspect the offences are related.

"Luckily there was no stock in that paddock at the time. The damage to the fences has been valued at about $700 but what is most concerning is the potential danger to road users in those areas," he said.

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