Kodak made the initial complaint to the ITC in January
The US International Trade Commission (ITC) has said it will investigate the makers of the iPhone and Blackberry, over technology used in their handsets.
The case was prompted by a complaint by camera firm Kodak against Apple and Research In Motion (RIM), the makers of the smartphones.
Kodak alleges the iPhone and Blackberry use technology for previewing pictures that infringe Kodak patents.
Kodak has asked the ITC to bar both firms from shipping the phones.
The camera firm said in January, when it filed the complaint with the ITC, it had been in talks with both firms "for years" to try to resolve the matter "amicably".
Both RIM and Apple declined to comment on the investigation.
The technology has previously been scrutinised in court. On 17 December 2009, an ITC judge ruled that camera-enabled phones made by Samsung infringed upon the Kodak patent.
Kodak has also filed two separate lawsuits against Apple in the US.
They were filed on the same day as the complaint to the ITC and claim Apple products infringe patents relating to digital cameras and certain computer processes.