Sky TV customers are unhappy last night after a number of free-to-air channels suddenly blacked out.
Some customers reported an outage to channels One, TV2 and TV3 shortly before 8.30pm.
Sky TV spokeswoman Kirsty Way said channels 1, 2, 3 and Movies Greats were off air for about 15 minutes last night, due to a technical fault.
"We have international vendors analysing exactly what happened," she said.
"On behalf of Sky I'd like to sincerely apologise for this rare interruption to TV viewing.
"We appreciate it will have disrupted Kiwis in some living rooms across New Zealand and we are working hard to understand why and ensure it doesn't happen again."
The outage came as TV3's The Block - the new season - aired.
Many viewers were unhappy with the interruption; venting their frustrations on social media.
"Missed the end of The Block. Thanks, Sky TV," one person wrote on Twitter.
"First time watching the TV in ages and Sky TV 1, 2 & 3 channels go black. This AB RWC marketing has gone too far," another wrote.
The issue has since been resolved.