An appeal for information has been launched after a flock of about 5,500 sheep vanished, leaving investigators to piece together how so many animals could seemingly disappear.

Detectives from the Rural and Stock Crime Squad believe the Dorper ewes and rams were taken from a property outside Blackall in Queensland’s outback, on the Blackall-Isisford Road, between February and May.

“Police estimate the value of the stolen Dorper sheep at more than $1.7 million,” Detective Senior Sergeant Paul Elliot said, making it one of Queensland’s biggest livestock theft investigations.

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The sheep were fitted with white National Livestock Identification System (NLIS) tags, which are designed to help trace livestock through the supply chain.

But investigators now face the challenge of working out how such a large number of animals could have been moved.

Police are particularly interested in speaking with anyone who saw suspicious stock movements, livestock transport activity or other unusual behaviour in the area.

About 5,500 Dorper sheep worth more than $1.7 million have allegedly vanished from a property near Blackall. Credit: Queensland Police

Livestock theft investigations can be complex, often spanning large geographical areas, Elliot said.

“We work closely with producers, saleyards, transport operators and industry stakeholders to identify offenders and disrupt criminal activity,” he said.

“Livestock theft can result in substantial financial losses and place additional pressure on farming businesses already facing challenging conditions.”

The Dorpers, a hardy South African breed known for their distinctive white bodies and black heads, are primarily raised for meat.

Their disappearance has struck in a region with deep ties to Australia’s sheep and wool industry.

Blackall, about 2.5 hours’ drive south-east of Longreach, has long been at the heart of Queensland’s wool industry and is home to the historic Blackall Woolscour, one of Australia’s oldest remaining steam-operated wool-washing facilities.

Anyone with information about the missing sheep or suspicious activity is urged to contact the Rural and Stock Crime Squad at Longreach or Crime Stoppers.