The otter was first spotted by Susan Dilks (18) at about 10pm on Monday last week after he got into the garden of her home in Welland Avenue, tripping the security light.

Keen to share the find with others, Susan grabbed her digital camera and captured several shots and even a short video of the otter in action.

She said: "It was a big shock because it was a big animal. I couldn't believe it myself. I got downstairs and said to my parents 'quick quick there's something in the garden it looks like a otter'. But as soon as my parents came to the window it had gone.

"I was trying to convince them it was there when it suddenly came back underneath the gate. The garden is quite small and we don't have a pond so I couldn't think why it would be in our garden."

The otter has become a regular visitor to the garden, returning the following evening and again on Sunday.

A keen animal lover, Susan has a National Certificate in Animal Care from Moulton College and works part-time at Desborough's West Lodge Rural Centre but this is the first time she has seen an otter in the wild.

She said: "I've never seen anything like it in the garden before. We went to Scotland about two years ago and didn't see one so to see one in the back garden was a shock."

The population of the European Otter declined in the UK last century due to river pollution from pesticides and other threats such as habitat loss and hunting but recent Environment Agency studies have shown numbers are on the increase.