SINGAPORE - A SingPost officer helped to rescue a cat from a locked Housing Board letterbox after a woman was alerted to the trapped animal by the sounds of mewing.

Ms Nurhayati Hashim, 22, was on her way home around 1pm on Friday (Sept 8), when she was startled by a cat mewing from inside a letterbox.

When she pushed the slat, the animal put out its paw, but she found the letterbox at Block 169, Bukit Batok West Avenue 8, locked.

She went to the corresponding unit but the woman who opened the door could not communicate in English.

The woman then called her daughter-in-law, who spoke to Ms Nurhayati over the phone and explained that they did not have the key to the letterbox. The woman was tending the flat for a tenant who was overseas, she added.

Ms Nurhayati called SingPost for help. A SingPost spokesman told The Straits Times that an Inspector of Post responded immediately.

He arrived at the scene at around 1.30pm, and opened the letterbox to release the black cat.

"The cat was fine when it got out. No injuries were seen," said Ms Nurhayati, who is unemployed.

She posted videos and pictures of her encounter on Facebook, which went viral, with more than 1,800 likes and 3,400 shares.

Ms Nurhayati said she also received a message from someone who wanted to adopt the cat, but she is unsure if she can locate it again.

The SingPost spokesman said this was the first time an animal has been found in a letterbox.

Cat Welfare Society (CWS) executive director Laura Ann Meranda said CWS will be working with the authorities "to verify if there was any deliberate intention to harm the cat by retrieving the closed circuit television footage".

"We appreciate the quick action of the resident and the SingPost officer who acted promptly to help the cat," she said.