When Mr Kalam Mohd Abu's wife saw a picture of him with police officers on Facebook, she thought he had done "something wrong".

In fact, the cleaner had done quite the opposite. On Sunday, he was working in Commonwealth Crescent when a woman in a sixth floor unit asked him for food.

Without hesitation, the 31-year-old said she could have his box of curry and rice that he had prepared at his dormitory the night before.

His act of kindness was noticed by some police officers who talked to him while on patrol.

When he explained that he was going to his storeroom to collect his lunchbox for the needy resident, the officers were so impressed by his selfless act that they took pictures with him and posted them on Facebook.

The post garnered hundreds of "likes" and on Wednesday, the Bangladeshi worker received official recognition for his kindness when he was awarded a certificate of appreciation by Tanjong Pagar Town Council.

Mr Kalam also won praise from his family, who found out about his deed only when his wife and family went online and saw him with the officers.

"She thought the police had caught me, that I did something wrong," said Mr Kalam, who has been working in Tanjong Pagar since he came to Singapore a decade ago. "But I said no, nothing wrong. This one's happy news."

The woman he helped had just had an operation and was not very mobile. "She cannot cook, cannot go to the market to buy (food)," he added.

Mr Kalam earns less than $1,000 a month but said he is "very happy" to be working in Singapore.

He spoke no English when he arrived here, but now speaks some, as well as a little Malay and even Singlish. He sends money back to his parents, wife, and two-year-old daughter, whom he has yet to meet.

Mr Kalam's supervisor, who declined to be named, said that this is not the first time Mr Kalam has given food to an elderly resident in the area.

"He has seen the elderly grow older, the weak become weaker and some have died over the years," he said.

"He has already been giving extra food to the elderly. That's why when the woman asked for food, his instincts kicked in.

"They're also comfortable eating the food because they already know him."

Mr Kalam said that he likes to help any "auntie" or "uncle" whom he sees around the estate.

Residents invite workers to gatherings on occasions like Christmas and New Year.

"They don't treat it as a place of work," Mr Kalam's supervisor said. "It becomes a home."