Wang said his wife and him were sleeping deeply until a sound woke them up at 4am. He saw a small figure standing near the bed, searching through his clothes.

"I thought that it was a child at first, but the figure was only 30 centimeters tall," Wang said.

"When I stood up, it rushed to the window with my trousers. My wife failed to grab it but noticed it had a tail."

Wang said he realized that it was a monkey when it looked back at him after passing through the iron bars on the window.

Some neighbors said that the monkey may have been searching for food, while Wang suspects that it was trained to steal.

He said he locked the window screen before sleeping, so maybe someone opened it and let the monkey in.

Wang said there was a similar case last October. His neighbor found clothes missing with certificates and tens of thousands of yuan in it when they woke up in the morning, but all the doors and window were not prized.

Yao Jianzhuang, an employee from the Shanghai Zoo, said it only takes about three months to train a monkey to do some acts, including stealing.