The legal action that mobile phone developer Sendo initiated last week against mobile operator Orange actually centres around technology developed by a manufacturer supplying handhelds to Orange, according to Sendo.

Taiwan-based High Tech Computing (HTC) supplies handhelds for the Orange SPV Smartphone, which Sendo claims infringes on its patent related to the design of a circuitboard. However, since HTC is located in Taiwan Sendo cannot sue it over a UK patent.

Instead, the company is suing Orange in the UK, which imports the HTC-made phone and sells it under its SPV Smartphone brand.

"It's regrettable, but we cannot sue HTC because it is based in Taiwan," Sendo spokeswoman Marijke van Hooren said on Friday.

Dai Davis, a consultant on IT law for UK law firm Nabarro Nathanson, said that it is common for companies to sue importers, especially when they have no patent for the technology in the country where it is manufactured.

A representative for Orange said that the company "strongly denies any impropriety" and that it is contacting the parties involved in the building of the handheld.

But even if Orange did not know about the alleged patent infringement, it could still be found culpable, Davis said, because patents are published and considered public knowledge.

"Ignorance is not bliss when it comes to patents," Davis said.

Representatives for HTC were not available to comment on the matter.