Chinese actress Zhou Xun and Chinese-American actor Archie Kao have finally confirmed their divorce after rumours of their split have been swirling the past three years.

Zhou, 46, married Kao, 51, in 2014, but they have rarely been seen together in public since 2016 and have had almost no interaction with each other on social media since 2017.

On Tuesday night (Dec 22), a photo of Kao kissing a long-haired woman was widely circulated online.

There was also a love letter from the woman posted on Instagram, in which she addressed Kao as "my love" and wrote in English: "There might be millions of roses in the whole world, but I am your only one, unique rose."

The Instagram account has since been set to private.

The two photos immediately started tongues wagging again.

On Wednesday, Zhou, who starred as the consort Ruyi in the 2018 television serial, Ruyi's Royal Love In The Palace, posted a message on Weibo wishing Kao well. In what was possibly a coordinated gesture, he posted an identical message to her three minutes later.

The actor confirmed the divorce with Taiwan's Apple Daily through a good friend, with the newspaper saying that he and Zhou divorced two years ago.

"I am surprised to receive so much attention today as I thought everyone was aware of our divorce," he was quoted as saying.

He said he is currently single, as Apple Daily said the woman in the photo was his ex-girlfriend, whom he dated after his divorce. He broke up with her more than two months ago in the United States, according to the newspaper.

Kao said he initially did not want to address the matter, but decided to do so after the photos were posted.

There were media reports which said the woman is a Singaporean flight attendant who is about 30 years old and currently living in Taipei.