BT Cellnet has found itself at the centre of a debate over whether businesses will be able to exploit the mobile Internet as freely as the Web.
Users and rivals have accused it of locking firms in to its own wireless application protocol (Wap) services, and not allowing free roaming of the mobile Internet.
Businesses fear such lock-ins would mean companies wishing to provide services on Wap phones would need to create special deals with service providers.
Telecoms watchdog Oftel is handling a complaint from Wap portal Fonedata.com about BT Cellnet not allowing a Mitsubishi Wap phone to access Wap content sites outside BT Cellnet's Genie Wap portal.
Now BT Cellnet is facing threats of more Oftel action after it was discovered that Motorola Timeport Wap users are also unable to receive direct Wap content outside the Genie portal.
Wap specialist MobileAge said BT Cellnet's services were similar to a Microsoft's Internet Explorer browser being pre-programmed to go to the Microsoft Network Web site. However, it is much more difficult for Wap users to intuitively find their way to other Web content.
BT Cellnet could be concerned that it would shoulder the blame for users unable to access poorly programmed Wap sites.
Wap development portal Anywhereyougo.com estimates that one in four Wap sites contain programming languages that make them inaccessible.
Oftel would not comment on specific complaints, but confirmed it was looking into the matter. A BT Cellnet spokesman said it was offering a four-digit unlocking code to pacify Mitsubishi Wap phone users. He would not comment on the Timeport situation.