BT Broadband customers have experienced connection problems following a fault in its Domain Name Servers.
The issue occurred last night (January 3rd) and meant subscribers were unable to access websites for several hours.
BT apologised for the disruption and immediately commenced an investigation into the cause.
The company was able to restore internet services, but was criticised by customers on Twitter for the outage.
This comes after BT experienced two outages in two days last summer.
A "substantial" power failure at Telehouse North, one of BT's internet connection partners in the Docklands, led to customers struggling to get online on July 21st.
This came a day after power issues at one of its internet peering partners' sites in London affected broadband services.