Dorchester residents are on the lookout for a runaway ape after a student took a picture of what appears to be a black primate on the loose in a park.

Terri Leigh Cox, snapped the mysterious creature bounding across the park on all fours.

The 17-year-old health and social care student said she was looking out her bedroom window when she saw the animal on the grass 100 yards away from her home in Dorchester.

"It was such a shock - I couldn't believe what I was seeing. It looked about the size of a small gorilla," she said. "It was walking like one as well, using its arms and feet.

"It was definitely a monkey because you could tell by its hunched back and the way it scampered across a field and up a tree. It wasn't a black dog."

Cox believes the animal is a pet primate that had escaped.

"I have no idea what the monkey was doing there. It could have escaped if someone was keeping it as a pet," she said.

Resdient Rob Samways, who walks his dog in the field, said: "I'll be keeping my eyes peeled from now on. I supposed somebody could have been keeping it as a pet and it has escaped."

Although the park is about 10 miles away from the popular Monkey World attraction in Wool, a spokeswoman for the sanctuary confirmed that all its monkeys and apes were accounted for.

"The image is not clear and it is difficult to make out, so we would be unable to confirm its identity," she said.

"I can confirm all of our rescued monkeys and apes are safe and well in the park."