Telecom is apologising for a technical problem which has left some of its overseas mobile phone users unable to receive or make phone calls and text messages, or access data.
A post on Telecom's website says it's been aware of the glitch since Tuesday morning.
The company is advising affected customers who need to make urgent calls, send texts or access data to obtain local SIM cards or log-on to an alternative wireless network.
Telecom says its staff are working around the clock to resolve the problem.
