A "joke" involving a Cambodian TV channel and a teenage girl who thought she was to be reunited with her mother has backfired.

The Mother's Day prank involved 13-year-old Autumn Allen appearing on MyTV variety show Penh Chet Ort (Like It Or Not) where she was told she was going to meet the mother she had not seen for years.

Viewers heard Autumn say she had not seen her mother since her father brought her back to Cambodia from the US, where her mother remained, the Phnom Penh Post reported.

The girl cried as she recalled: "She held me and kissed me and told me that she would always love me."

Producers then told viewers they were going to make the "dream to meet her mother come true".

The meeting was preceded by a lengthy build up expected to lead to an emotional climax that would satisfy both the teenage girl and the audience.

But, to the shock of Autumn and the viewers, the "mum" she met was cross-dressing comedian and game show judge Chuop Rolin.

"What are you thinking? Did you think it was real?" one of the presenters asked the teenager and singer, who has performed on TV on several occasions.

"I don’t know," Autumn said with a nervous laugh.

Social media users have put the boot into producers, who have been forced to apologise for the cruel stunt.

"Such a brainless and shameful trick from MYTV! How can you play with her feeling like this?" posted Kanika Chhit on Facebook.

Independent political analyst Ou Virak weighed in too.

"The producer was stupid and brainless and heartless by playing around with the mind and heart of a 13-year-old girl in this way," he said on Facebook.

"They lied to this girl that her mother she hasn’t met for a very long time will be reunited on live TV, only to be presented with a cross dressing comedian."

The show has admitted the stunt was a "mistake".

"We produced that programme to make Allen and other people happy," said Penh Chet Ort producer Taboi.

"We wanted to send Allen a message that although she has no mother, our team loves her as family so that we play with her to make her smile," he said.

Autumn herself seemed to take the joke reasonably well, telling the Phnom Penh Post: "On that day I was very excited because I thought [my mother] was actually coming.

"At the moment I was sad that I could not see my real mother, but I had fun doing the show.

"Initially I was disappointed, but Rolin made me laugh so I had fun on the show.

"My dad was very proud of how I handled myself in the situation. He took me to a nice restaurant afterward."

She added: "I tried to contact my mother several times when we moved to Cambodia but she kept changing her phone numbers.

"My dad thinks she lived in Scottsdale, Arizona, but we don’t know for sure. Yes, I miss her and do want to meet her."