Nikon has issued a recall on more than 700,000 rechargeable batteries used in its digital SLR D100, D70 and D50 cameras.

The EN-EL3 battery pack has a recently discovered flaw that means the battery can overheat and even melt in some circumstances. The cause is thought to be a short circuit within the power pack.

"Through strict quality control procedures Nikon has detected that on rare occasions some rechargeable Li-ion batteries of the type EN-EL3 for Nikon digital SLR cameras may become defective, resulting in overheating during recharging," said the company in a statement.

"Investigations have clarified that the cause of the defect is not a design fault, but has resulted from a problem in a manufacturing process that occurred during the production of this battery type between May and September 2004."

The firm said it has learnt of five cases of battery failure, of which two were in Europe. No injuries have been reported so far.

Nikon has issued an advisory showing which serial numbers identify the defective batteries.