US-based law firm Kershaw, Cuttiner and Ratinoff is rallying users affected by the iPhone antenna problem to bring a class-action lawsuit against the iPod maker.
Kershaw, Cuttiner and Ratinoff, a firm that describes itself as "Lawyers who fight", has posted a message on its website, claiming that it is investigating the iPhone 4 reception problem, referred to in certain places online as the "iPhone Death Grip".
The message reads: "If you recently purchased the new iPhone and have experienced poor reception quality, dropped calls and weak signals, we would like to hear from you."
The iPhone 4 launch - Apple's most successful ever, with 1.7 million units sold in the first three days - has since been marred by a number of issues that have arisen with the device.
Some users have reported that the Retina Display screens on their devices suffered from yellow discolouration, volume buttons had been fitted in reverse on some units, and others found that an issue relating the design of the phone's antenna led to poor reception and dropped calls when the device was held in a certain way.