Scores of allotment owners across Oxford have been put on red alert after a spate of vegetable thefts was blamed on the rising cost of food.

The warning was issued after broad beans, onions and sweetcorn were stolen from Elder Stubbs allotments in Cowley on separate occasions last week.

Last night, Oxford City Council said it was the first time it had heard of food being stolen from allotments in the city.

Allotments holders said they believed spiralling food prices were to blame for the thefts.

Sally Robertson, whose plot has been raided three times in as many weeks, said: "I do think rising food prices played a substantial part in it - especially because it was organic vegetables, which sometimes cost a bit more at the supermarkets. Having the allotment had restored my faith in society because everybody is so nice down there.

"But to then go and have it spoilt has really disillusioned me. I just think it is despicable."

Miss Robertson, 26, from Badgers Walk, and her sister Jane, took on the plot at the mental health charity-owned site a year ago to cultivate home-grown produce.

The pair spend about six hours each week tending the plot, for which they pay £12.90 a year in rent.

But on Tuesday, June 10, Miss Robertson noticed her crop of globe artichokes had been slashed with a knife and killed.

Two weeks later about 20 broad bean plants were dug up and stolen - just as they had become ready to eat.

Soon after that, 15 ripe sweetcorn plants were swiped.

Miss Robertson said another plot holder had reported his onions missing.

She added: "I think the people that committed this crime are selfish and unfeeling.

"Although the price of food is increasing that's no excuse to take what's not yours."

She said she would now be talking to the allotment's management committee about installing CCTV.

Phil Creme, estate manager for Elder Stubbs Allotments, said one or two other crops had been damaged, and added: "The price of food is increasing and that could well mean allotments are targeted.

"People are taking up their crops slightly early because they don't want them to be pinched."

Mike Gass, the council's allotment manager, said plots were frequently vandalised, but he had not heard of vegetable thefts in the past or elsewhere.

A police spokesman said: "The Cowley neighbourhood policing team will be liaising with the management at the site.

"Allotments are often vulnerable to petty crime, so we advise plot holders to look out for each other's property and report anyone acting suspiciously."

Have you had fruit or vegetables stolen from your allotment plot? If so, call our newsdesk on 01865 425444.