A Campbells Bay couple seem to have a mysterious problem with their alarm clock. For some reason, their two alarm clocks have gone off at the exact same time for four consecutive mornings, despite not having been set, they say.

The first night, the travel clock went off at 1am.

"It was a nuisance, but we turned it off and thought no more of it," says the woman, a North Shore identity who asked not to be named.

After the same thing happened the following evening, her husband thought maybe the batteries were going, so changed them.

He set the alarm for 9am, but again it rang at 1am on the dot.

That night, they put the clock at the far end of the house and decided to use another alarm clock, again setting it for 9am.

"We made sure that the alarm was not set and went to bed at 11pm, but were awakened by an alarm bell ringing," says the woman.

When she looked at the time, she was in disbelief. It was again 1am.

"What's the significance of their ringing at 1am? None were set to go off at that time."

She says they are worried and sleep deprived.

Hamilton clock manufacturers Clockworld manager Christine Frampton says there is no explanation for the clocks doing that.

"It's really weird."