A thief who stole packages from a rural drop-off box in Glenavy probably has got more than expected – and more than wanted.

Morven Piggeries owner Gus Morton went to the drop-off box, used by the rural community, on Tuesday morning expecting to find a $750 package of pig semen.

Morton has the semen delivered from Christchurch every week by the Knightrider bus service.

For the first time in 12 years, the semen – in a white polystyrene chilly container – was not in the box. At first Morton thought the bus driver had forgotten to leave it but the driver remembered leaving the package with two other packages in the box.

Those packages are also missing.

The theft meant Morton had to travel to Ashburton and pay another $750 for a new supply of pig semen the same day the original package was taken.

The semen was to have been used to inseminate 15 sows, and was from purebred large white pigs.

"I laughed – probably through frustration – because it's of nil value to anybody," Mr Morton said.

"While it's very, very frustrating it's more the inconvenience because there's that many things to do in a day."

Kept at 17 or 18 degrees Celsius, the semen had a shelf life of about five to seven days, but if it got too cold or too hot it degraded, he said.

"I think I said [on discovery of the theft] `I hope like bloody hell he drank it'."

Waimate police constable Paul Alden said surveillance tape from the store showed the drop-off box was raided between 3.45am and 4.45am on Tuesday.