Twitter's t.co link shortening service went offline yesterday after domain registrar Melbourne IT mistakenly put the domain on hold.
The Next Web reported that a 40-minute outage made all links "automatically shortened by Twitter... dead" from about 4.32pm yesterday, Australian Eastern Standard Time.
A CNET report revealed that user error at Melbourne IT - the domain registrar Twitter uses for t.co - saw the domain taken offline.
A spokesman for Melbourne IT told iTnews that the error occurred in the course of a phishing investigation.
"Melbourne IT's domain policy team is active in investigating requests from registries and the public about potential abuse of domains (including phishing sites) registered via Melbourne IT or its resellers," the spokesman said.
"We take each request seriously and if our investigations show that there is clear evidence of phishing or malware we can shut the domain down to protect consumers.
"Yesterday in the process of actioning a phishing complaint, our policy team inadvertently placed the t.co domain on hold.
"The error was realised and rectified in approximately 40mins and t.co links again began working."
The spokesman said Melbourne IT had been "in contact with Twitter" and that it was reviewing its "investigation and verification processes".
Twitter has only made a brief statement about the outage, acknowledging it occurred while saying it has been resolved.