Wiwik, who is fluent in Cantonese, had on December 7 taken a call from a man who claimed to be her 78-year-old employer's son and said he was on his way back from Canada.
Suspecting it was not the son as he did not address her by name and his voice was unfamiliar, Wiwik asked her employer whether her son had left Canada and was told he was still there.
The man called again next day and asked Wiwik to arrange a transfer of 20,000 yuan (HK$22,390) to a bank as he had been arrested while visiting prostitutes in Shenzhen and needed the money for bail. But Wiwik called police.
A domestic worker in Hong Kong for more than 10 years and with this employer in Wong Tai Sin for almost two years, Wiwik said: "It's something I should do. It's nothing big."
Wiwik also said she watched Police Report on television, which among things teaches people how to recognize fraudsters.
The same day a scammer was trying to set up Wiwik another domestic worker, Istikomah, who can also speak Cantonese, was told by her 85-year-old employer in Kwun Tong to deposit HK$30,000 in her younger son's name as she had received a call.
But Istikomah suspected it was a fraudulent call as "the son normally sends his mother money instead of asking" and the caller had asked her employer not to tell the elder son of the transaction.
Istikomah texted the younger son to check if he was in need of money and was told he had not called. The son then called police.
The two Indonesians received appreciation letters from the police yesterday.
Also at the ceremony was Indonesian consul general Tri Tharyat, who said he was moved at seeing the two helpers receiving accolades.
"These small things can have a big impact on society," he added.
Assistant regional crime prevention officer for Kowloon East, Wong Poon- yam, said combating phone fraud is a priority, but these were the first cases reported by Indonesian helpers.
"We didn't know Indonesian domestic workers can speak fluent Cantonese," Wong admitted. "It was after these reports we realized we have to tell this community more about preventing phone scams."
There were 1,138 reported phone scams last year compared to 2,756 in 2015. Monetary losses dropped to HK$200 million from HK$300 million.