8 July 2010 Last updated at 12:00 ET

Australian vegetables poisoned as police probe sabotage

Around four million tomato seedlings were poisoned

Police in Australia are investigating the poisoning of seven million vegetable seedlings, including tomatoes, aubergines and melons.

Detectives believe a herbicide was injected into the irrigation system at a nursery in northern Queensland.

The Australian farm minister described the poisoning at a Queensland nursery - the fourth such incident in eight years - as "sabotage".

Farmers and analysts say the price of vegetables will increase as a result.

The cost of the damage is estimated at AUS $23.5m (£19.7m; $20.3m US), said Denise Kreymborg of the regional growers' association.

Grudge or vandalism?

Police are investigating possible links to the other poisonings in the region, which produces most of Australia's vegetables during the winter months.

"It could be a grudge, it could be competition-based... or it could be an act of vandalism," said Dave Miles, the acting police inspector for Townsville, near Cairns.

"I don't think it's just a local vandal," Ms Kreymborg said, according to the Associated Press.

"Obviously they knew what they were doing, as it was a pretty technical act they've done. But we don't want to contaminate the investigation by pointing fingers."

Workers at the Supa Seedlings nursery, which supplies around 30 regional growers, noticed plants wilting from 20 June.

The bulk of the poisoned plants - around four million - were tomato seedlings. Some of them had already been transplanted on farms.

Around 350 hectares of production land, with the capacity to grow about 200 tonnes of fresh produce, have been affected.

The vegetables were destined for sale across Australia and for export to New Zealand and the Pacific island nation of Vanuatu.

Prices in all three countries are likely to spike over the next few months until produce from other regions comes onto the market, reports say.