Telstra customers across the country have experienced issues accessing the internet today, with the telco facing an "unplanned outage" affecting its broadband and wireless data networks.
The issue arose when "planned works" on the power system at one of Telstra's Sydney data centres caused a power outage, and the centre's standby power unit also failed.
Telstra said it is investigating why the backup power failed, but added that the issue only affected "a small number of customers nationally".
In addition to broadband and wireless access, the issue also knocked out some of Telstra's "digital services" and online applications including Telstra MyAccount, 24x7 apps, LiveChat and prepaid recharge services from both Telstra and its Boost mobile brand.
The issue emerged on the morning of January 14 as customers took to social media to complain of slow internet speeds or a complete lack of connection, with others criticising the company for keeping customers on hold for extended periods on its customer service line.
All services have now been restored and customers will need to restart their modem in order to connect. We apologise for any inconvenience caused to customers this morning.
A spokesman for the company also confirmed that Telstra was continuing to experience issues with some online applications including those mentioned above, such as MyAccount and prepaid recharging.
"We are working on restoring services as soon as possible and apologise for any inconvenience," the spokesman said.
Updated at 2:45 p.m. AEDT to include additional comments from Telstra.