The iPhone is equipped with a possible application 'blacklist', which could allow Apple to remotely remove certain applications, claims one researcher.

Researcher Jonathan Zdziarski found a file buried deep within the iPhone's firmware that allows the handset to contact an Apple server and retrieve a list of applications which could then be removed from the handset.

The list could be used by Apple to remove malicious iPhone applications or software that violates the handset's terms of service.

In a follow-up blog posting, Zdziarski noted that little is known about the function of the list and cautioned users against jumping to conclusions as to what, if anything, Apple does with it.

"We do not know whether this mechanism is active or what exactly it does," he wrote.

"It might vaporise applications. It might simply prevent them from using the GPS. It might do nothing except upset the privacy advocates who don't like their iPhone calling home."

"For all we know, it could trigger world war three, or it could cause some computer somewhere to spit out recipes for buttermilk pancakes."

Apple did not return a request for comment. The company has a history of not commenting on items it considers to be rumours or unsubstantiated claims and has traditionally been tight-lipped on security matters.

The relationship between Apple and those who want to write software for the iPhone has been strained at times, to say the least.

Fearing security and stability problems, the company had initially restricted iPhone development to browser-based applications, creating an underground market for applications on unlocked iPhones, which often experienced compatibility problems with firmware updates.

While the App Store and iPhone SDK gave developers an avenue to develop and distribute iPhone software legitimately, some apps are still distributed outside the App Store, either by the developer's choice or due to being pulled from the service by Apple for rule violations.

Two such pieces of software were added this week when Apple removed NullRiver's NetShare connection-sharing application and I Am Rich, a $999 vanity application that did little beyond placing a glowing gem on the user's screen.