Families in Oxford are paying hundreds of pounds extra a year on basic groceries as costs soar, an Oxford Mail investigation has revealed.

Experts warned scores of families are at risk of being plunged into debt by the spiralling costs of food in the city.

An Oxford Mail test comparing the cost of a basket of 20 basic groceries with their price just under a year ago revealed the bill had risen by 11 per cent.

We visited Tesco in Cowley to buy a selection of items on a Tesco receipt dated May 2007.

The bill - which included eggs, cereal, cheese, milk, fruit, margarine, quiche and baked beans - had increased from £33.93 to £37.82, a rise of £3.89 or 11 per cent.

A pint of semi-skimmed milk, commonly used as an indicator of food-price inflation, had risen by 6p - an increase of 17.6 per cent.

Carole Roberts, manager of Rose Hill and Donnington Advice Centre, said the rising cost of food would hit many hard. She said the centre used to deal with one or two bankruptcies a year, but over the past six months had dealt with at least one every four weeks.

Mrs Roberts said: "When we start filling in the income sheets, the amount spent on food and gas and electricity, which people have got to have, has more or less doubled in the past six months.

"People are very stressed."

She said financial problems could cause mental health issues such as depression and relationship difficulties.

And she added: "Oxford is a very deceiving city. It has the highest rate of low-paid workers in South East England.

"We try to educate people into doing a budget and sticking to it. But, due to rising prices, they make a budget and next month they're out of pocket again."

Jane Benyonok launched the Cowley-based Community Emergency Foodbank three weeks ago because she was worried about people in Oxford not being able to afford food.

The 61-year-old from Bladon, near Woodstock, said: "I'm sure that over the next six months it's going to get very, very busy because of the rising prices of food and the credit crunch.

"I just know that this is the right thing to be doing because of the fact that people are going to be in dire need, particularly with the increasing amount of debt people are in anyway, and this just adds to the problem.

"There are a lot of people who on the outside may look quite well off but something has gone wrong, or they haven't been paid."

Figures released by the Office for National Statistics last monthApril showed wholesale food prices rose by 8.5 per cent over the past year.

According to the price comparison website mysupermarket.co.uk, a basket of 24 staple foods has risen by an average of 11 per cent in the past 12 months - supporting the Oxford Mail's findings.

To an average family of four with a weekly grocery bill of £100, that represents an extra £572 per year.

Last week the Oxford Mail revealed motorists across the county were paying an average of £5 a gallon for petrol for the first time as the price of oil continued to soar.