A South African inventor has developed a new security feature for mobile phones to help combat theft.

The device can place the owner's photograph and details on the background of a mobile phone screen without interfering with any other functions.

The inventor, Edward Modisakgosi, hopes the measure will help cut the rising trend of handset theft.

But one mobile phone operator has cast doubt on whether it would be effective.

Uncertain benefits

Mr Modisakgosi, told the BBC's World Business Report that he hoped to prevent thefts by making it financially unviable for thieves.

"Removing the financial part of it makes the whole exercise useless," he said.

After hearing about the device on local television, marketing consultant Axel Von Gerlarch offered to help sell the product internationally under the name Cell-pic.

He is now in talks to licence it in a variety of countries.

It took Mr Modisakgosi 18 months to get his idea to the production stage, but telecom companies have expressed doubts over whether it will work.

Little deterrence?

Joan Joffe, an executive with Vodacom, South Africa's biggest mobile phone operator, told the BBC's World Business Report she believed the concept might help, but would do little to deter people who acquire stolen phones.

"They wouldn't care too much if somebody else's picture was on it," she said.

The main problem however, is that many stolen phones find their way into neighbouring countries where Vodacom's current methods of detection do not work.

South Africa has about 10 million mobile phone users and one of the highest crime rates in the world. Phone thefts are commonplace.

"In our own network thousands of phones are reported to us as being stolen every month," she said.

"Vodacom is a network operator and we are not in the private investigative business," she added.