CHECK what's behind your fish tank or risk a fire – that's the warning from Broadwell couple Carol and Keith Powles.

The smell of burning at their home in Edinburgh Place had Mrs Powles mystified until she went to feed the fish.

To her horror she found an envelope smouldering next to the fish tank that had acted as a giant magnifying glass to set her husband's tax return alight.

She and husband Keith are now warning others who own similar tanks to be careful about what they leave nearby because of the fire risk.

The sun streaming through the window of their home in Edinburgh Place, Broadwell cut a hole the size of a 50p piece through the envelope, the folded tax return and out the other side.

The envelope was in a letter rack standing on a wooden cabinet.

Mrs Powles said: "There was a smell of burning but I couldn't find it. I was about to go out and I decided to go and feed the fish.

"That's when I saw the envelope, it was smouldering and there was a hole cut through it.

"When I picked it up the you could see the sunlight on the other letters like a laser.

"It's the thought of what could have happened if I hadn't had found it.

"I'd turned the blinds and I was going about an hour and a half later, that's how quick it was.

"The day before I would have been out at work so anything could have happened."

Husband Keith, a former firefighter, said: "I've never come across anything like this before. You wouldn't think the sun was that strong in January but I think people should check their own tanks."