As per reliable reports, Apple is making arrangements to test 'Siri', the 'personal assistant application' introduced along with 'iPhone 4S', in older devices also.

The company intends to upgrade the smartphone on account of the application. However in all probabilities, the feature may become compatible backwards.

This information has been through a blog which said that the employees were given the handsets by the company to test the application secretly.

The application at present runs only on iPhone 4S, but with the help of a software, Siri's features can be incorporated in older devices as well.

The developers as well as hackers are interested in a port, which may not be required if the software update is done forthwith by Apple.

Apple's claim that the iPhone's two cores were needed to run the personal assistant application was proved wrong when a website showed the app running on iPhone 4.

To avoid unwanted security risks, Apple has withdrawn the handsets on trial.

These unpleasant incidents were quite embarrassing for the large company, Apple, whose vice president for global security, John Theriault had to quit the company regarding these issues, though Apple stated that he has only retired.

Theriault was involved in the investigation to the lost iPhone 4S prototype which showed Apple employees disguising as police officers to enter a suspect's premises.