Police have issued a warning after an elderly woman from Southern Asia living in Beijing was swindled out of 1 million yuan.

She was the fourth victim to fall for a telephone scam since June, the Entry and Exit Administrative Department of the city's Public Security Bureau said on Monday.

Narreerat Arisara, 74, from Thailand, is a retired flight attendant and was living in an apartment with her adoptive daughter near Happiness Street, Dongcheng district, said Lin Song, press officer with the department.

Lin told METRO on Monday that the woman was conned on July 10 after her daughter went shopping and left the elderly lady at home. The victim received a strange telephone call telling her the landline in the home was about to be cut off because of money owing on the account.

Arisara told the caller there was not a phone in the home in her name but the man on the line said the computer system showed that she had three lines. The man said the lines had been used to dial several long-distance numbers and he said she owed 10,000 yuan, said Lin.

The man told Arisara that the telecommunications sector had encountered many such cases and said "it's possible your private information has been usurped and we will immediately report this to the police," said Lin.

Five minutes later, the worried woman took a call from a caller using a mobile phone who claimed to be a police officer from the Public Security Bureau.

The fake cop claimed police had found that a suspect had registered several phone numbers and bank accounts in her name.

He said the suspect was engaged in illegal money laundering and told her the amount of money involved was up to 10 million yuan.

The fake cop said they would need to freeze all her bank accounts and said she could temporarily transfer all her savings to a designated bank account so she could continue to use her money.

The victim was afraid she was implicated in crimes and rushed to the nearest bank and followed the phony police officer's advice to transfer the money into the account number he gave her.

When the ATM machine showed that the transfer was successful, the con man hung up.

Later, Arisara told her daughter about the episode and they realized she had been swindled and reported the matter to police.

Lin said the number of such telephone frauds has dropped dramatically because potential Chinese victims are more aware of the risks, but he said some people, such as foreigners in the country temporarily, are not aware of the risks and might fall victim to swindlers.