Sources have confirmed that T-Mobile has been purchasing a number of unlocked iPhone 3GS handsets and offering them to select customers in return for extending their T-Mobile contracts reports The Telegraph.

Apparently, the offer of an unlocked iPhone 3GS only applies to T-Mobile customers who have at least a £70 per month contract, and is also made at the discretion of the customer service adviser who deals with the account.

Word is this offer is being offered to some long term T-Mobile customers who are considering switching to O2 to gain the iPhone 3GS, thus T-Mobile offers the unlocked iPhone 3GS as an incentive to stay with T-Mobile. So in a roundabout way it appears O2 has already lost its exclusivity over the iPhone 3GS.