The Chinese foreign ministry has said a Canadian woman is undergoing “administrative punishment” for working illegally, after Canada’s government said a third Canadian had been detained in China.

Chinese state security agents last week detained the former diplomat Michael Kovrig and the businessman Michael Spavor, saying both Canadians were suspected of endangering state security.

The detentions followed the arrest in Vancouver of Meng Wanzhou, the chief financial officer of the Chinese telecommunications corporation Huawei. Meng was arrested at the request of the US, which has been engaged in a trade war with China.

China’s foreign ministry spokeswoman, Hua Chunying, identified the third Canadian as Sarah McIver, saying she was serving “administrative punishment” due to “illegal employment”. Hua did not elaborate.

“What I can tell you is that China and Canada are maintaining clear consular communication,” she told a daily news briefing.

Hua, when asked if McIver’s case was connected to that of Kovrig and Spavor, said the nature of the cases were different, given the other two were accused of endangering national security.

Hua referred further questions on McIver to the ministry of public security. It did not immediately respond to requests for further comment.

The Canadian government has not identified the third person, though news reports in Canada have said it is McIver, and that she was an English teacher being held because of “visa complications”.

Canada’s prime minister, Justin Trudeau, urged caution on Wednesday and said he would not be “stomping on a table” after China detained the third Canadian. He said he was asking China for more information on the detentions.

The latest incident was “a very separate case” from the other two, Trudeau said. The Canadian government has said several times it saw no explicit link between the arrest of Meng, the daughter of Huawei’s founder, and the detentions of Kovrig and Spavor.

But Beijing-based western diplomats and former Canadian diplomats have said they believed the detentions were a “tit-for-tat” reprisal by China.

China has demanded Meng’s immediate release and summoned the Canadian and US ambassadors to complain about the case. Meng has been accused by the US of misleading multinational banks about Iran-linked transactions, putting the banks at risk of violating US sanctions.

She was released on bail in Vancouver, where she owns two homes, while waiting to learn if she would be extradited to the US. Meng is due in court on 6 February.