The fruits remained firm for 45 days, three times as long as normal tomatoes which start to wilt after just 15 days, researchers said.
The team believe that the breakthrough could also lead to an extended shelf life for other fruits, including bananas, and see the cost of their production tumble.
They lengthened the life of the tomatoes by “turning off” genes linked to the production of two enzymes which cause the fruit to start to ripen.
Similar chemicals are involved in the maturation of other fruits, meaning the technique has the potential to extend the lifespan of mango, papaya and bananas as well as tomato.
The alterations did not cause any other changes to the plants, the researchers said.
The new tomatoes grew normally, matured at a typical rate, and produced the same yield as normal tomatoes, according to the study, published in the Proceedings of the National Academy of Sciences (PNAS) journal.
However, the new fruits were more than twice as firm as normal and stayed firm for much longer than other tomatoes.
As much as 40 per cent of harvested fruit can be wasted because it ripens too quickly, the researchers from the National Institute of Plant Genomic Research in New Delhi, India, estimate.
“Overall the results demonstrate a substantial improvement in fruit shelf-life,” said Dr Asis Datta, who led the study.
“The engineering of plants with (this technique) provides a strategy for crop improvement that can be extended to other important food crops.”
However, it could be years before the fruits, still in the experimental stages, are available in Britain, if ever.
The big supermarket chains, including Tesco, have a policy against stocking GM foods on their shelves.
GM crops, which opponents have dubbed ‘Frankenstein food’, can also be sold in Europe only if they have passed rigorous safety tests and European law states that GM foods have to be clearly labelled, including when they are sold loose.
However, campaigners have warned that there is no compulsory labelling of meat or dairy products from animals which have been fed on GM crops, and that any long-term problems from eating the foods is still unknown.
Although GM foods can only be planted in Britain as part of a trial, and even then only under strict conditions, millions of hectares of the crops have already been planted in the Americas.
Pete Riley, from campaign group GM Freeze, said: “The majority of the public are very sceptical about the benefits of GM foods and I don’t think that this will do anything to persuade them.
“We have survived for millennia without needing to extend the shelf life of fruits and vegetables.
“Also, as many vitamins decline after fruit is picked this product could be less nutritious than other tomatoes.”
He added that not enough was known about the long-term safety risks of GM foods.
“It is difficult to design a test to show whether there are long-term dangers to human health,” he said.
The fruits are not the first genetically modified tomatoes to have been created.
In 2001 scientists announced that they had made tomatoes unusually high in natural antioxidants, called flavonols, which they said could help ward off illnesses including heart disease and cancer.