Hi-tech, modern satellite tracking equipment may be used to crack the age-old crime of sheep rustling.
The FUW believes the sheep thefts could be even more widespread
Officers at Dyfed-Powys Police are considering the move in reaction to a steep increase in thefts of the animals.
A new survey by the Farmers' Union of Wales (FUW) shows that thousands of sheep are going missing each year.
The worst hit county is Powys where 3,000 worth £200,000 have been reported missing in the past year.
Rustlers have stolen more than 1,000 from the remote village of Llangynidr, near Crickhowell, in the past 12 months alone.
Carmarthenshire, Ceredigion and Monmouthshire are also rustling hot-spots.
In a separate initiative in the old county of Montgomeryshire, the FUW said farmers, police and Powys County Council had held talks about narrowing the width of farm gates to five foot to make it harder for vehicles to access fields.
Some livestock owners, in the Newtown area, are even considering taking their sheep off the land because of rustling.
FUW survey on sheep thefts
1,000 from Llangynidr, near Crickhowell
487 from Brecon to Builth Wells area
530 in Monmouthshire
150 ewes from Llandinam near Newtown
115 from Ponterwyd near Aberystwyth
23 from Llandysul
270 from Llanllwni, Carmarthenshire
Chief Inspector Steve Hughson, of Dyfed-Powys Police in Brecon and Llandrindod Wells, said: "The satellite tracking system is certainly an option we are considering.
"But it is very much in the early stages and cost and the feasibility of the scheme needs to be assessed.
"It's something we've used before to track stolen quad bikes. It sounds hi-tech I know, and we would implant sheep in areas we have identified as high risk.
"It's a good idea and could reduce thefts which have totalled £200,000 in the last 12 months."
The chief inspector, a farmer's son, added: "It's difficult to assess whether there's been an increase in rustling or whether there's been a increase in the amount of reported cases.
"But we take sheep thefts very seriously. Police and trading standards officers are working together along with other agencies to solve this problem."
"The people doing this know what they are doing and are closely associated with farming," he said.
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The FUW president Gareth Vaughan urged people to use camera phones to capture images of rustling.
"The results are extremely worrying, and indicate that there are experienced gangs operating in parts of Wales who may be stealing to order," he said.
"Virtually everyone has a mobile phone, and mobiles with digital cameras are the latest must-have gadgets.
"I would appeal to anyone who has one of these camera phones and who sees something that looks suspicious to take a photograph of the incident.
"Photographs of lorries, trailers and number plates could be extremely useful."
Dillwyn John, who has 900 sheep on his farm at Cwmtaff, near Merthyr Tydfil, has fallen victim to sheep rustlers this year and over the last three decades.
"I estimate that I have lost as many sheep over the last 31 years as I now have on my farm," said Mr John. "It's a big problem in these parts."
With the regulations governing sheep identification, it would be extremely difficult for the thieves to sell them to other farmers or to licensed abattoirs, said Gareth Vaughan.