Ottawa (CNN) A third Canadian citizen, Sarah McIver, has been detained in China, Prime Minister Justin Trudeau has confirmed, but he denied it was linked to the arrest of a Chinese executive in Vancouver this month.

Speaking to reporters Wednesday, Trudeau said he was taking the matter "extremely seriously" but the detention was more "routine" than two earlier cases.

"We are still very much in the situation of collecting more information on this and I wouldn't want to say anymore than that," he added.

Chinese Foreign Ministry spokeswoman Hua Chunying wouldn't confirm McIver had been detained, but said on Thursday that the Canadian had received an "administrative penalty (for) illegal employment."

Hua added that McIver's situation was different from the two other Canadian detainees. "The previous two have been put under compulsory measures by state security on suspicion of endangering China's national security. This person was given administrative penalty," she said.

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