Truphone, the VoIP operator who sprung to awareness following Orange and Vodafone blocking its service on the popular Nokia N95 has won another battle in the courts, this time against T-Mobile.

Following the operator blocking the service, which gives you a separate number, on its mobile phones over what it claims is an unfair pricing hike, Tru-Mobile, the company behind Turphone, has been granted an injunction forcing T-Mobile in the UK to interconnect with Truphone and allow the service to be active once more.

In its court documents, Truphone said T-Mobile was "abusing its dominant position" by not putting its numbers through.

"We are not commenting on the current litigation" a T-Mobile spokesman told Pocket-lint.

Mobile operators have been caught in a difficult situation in recent times has VoIP services threaten to damage their traditional revenue streams.

Truphone for example, works by routing the calls via a phone's Wi-Fi connection when handsets are within range of a wireless hotspot allowing users to save on voice calls while the operator loses out.

This latest commercial dispute, which is still on going, shows the fine line mobile operators and companies working with them have to tread.

The ruling is the first time that interim relief has been awarded against a mobile network operator under the Competition Act.

We will keep you posted.