A new strain of wheat pumped full of iron has been created by British bio-engineers.

The genetically modified cereal produces a white flour containing twice the normal amount of iron.

Scientists believe the levels, significantly higher than those in any commercially grown variety of wheat, could help alleviate iron deficiency around the world.

Dr Janneke Balk, from the John Innes Centre plant science institute in Norwich, said: "This breakthrough means that higher levels of iron from the wheat itself could replace added iron in everyday items such as white flour and breakfast cereals, helping the estimated one billion people that suffer from iron deficiency worldwide."

Iron occurs naturally in wheat but is largely found in the outer parts of the grain that are discarded during the production of white flour.

The inner starchy part of the grain from which white flour is milled, known as the endosperm, only has low levels of iron. To create the iron-enriched wheat, the scientists introduced a transporter gene to direct more iron into the endosperm.

Iron uptake and transport in plants is highly regulated because, although essential for growth, the metal is toxic at high concentrations.

The scientists, whose work is reported in the journal Plant Physiology, managed to achieve greater accumulation of iron deep inside the wheat grain without any negative impacts on plant health or yield.