A popular Chinese reality show featuring fake father-daughter pairs has been accused of showing inappropriate relationships between adults and children.

The fourth season of the reality show Dad, Where Are We Going pairs "intern" fathers, all celebrities, with children who are not their own. In previous seasons, the show only featured celebrity dads and their real children, but a government ban on the "overuse" of celebrities' children forced the show to change.

In this season, 23-year-old Olympic athlete Dong Li is designated as "father" to 4-year-old Cui Yahan. He takes care of the little girl several days a week, eats and sleeps with her, and is present when she bathes.

Critics slammed one episode in which the girl told Dong that when she grows up, she wants to marry him, as well as to an interview in which Dong said his dream girl is Arale, Yahan's nickname.

The show's production company, Mango TV, fanned the flames by posting an online video clip set to a love song and captioned "Dong and Arale's interpretation of Let's Fall in Love", referring to a famous Chinese dating show.

However, the pair's popularity has triggered concerns among parents and experts. Some have claimed that the popularity of the show may mislead the public about appropriate adult-child relationships and make children vulnerable.

A mother-to-be published an open letter on Sina Weibo, expressing her anger that the show's producers have edited the show to make the pair look like a couple.

"If she were your daughter, would you ever let her stay with a strange man wearing only underwear? Would you ever allow a 23-year-old man to tell the media that his ideal type of girlfriend is your 3-year-old daughter?" the woman wrote.

However, others were quick to defend the show against the accusations.

"I don't think the pair are creepy. They are so adorable. Please don't exaggerate just to scare the public," a micro-blogger said.

The program responded via micro blog, saying the critics are "over-interpreting".

"The clips of Dong's words were intended to show his paternal love, but these clips were distorted and interpreted out of context, misleading netizens," according to the statement.

The statement added that Dong never stays alone with the girl. Cameras are placed everywhere, and the girl has a female director to help her change her clothes and bathe, it said.

However, the explanation has irritated some child protection experts, who have called for the issue to be taken seriously.

Jiang Jing, procurator at the Jinniu district procuratorate in Chengdu, Sichuan province, said that the show sets a bad example for sex education and is too flippant in its treatment of the safety risks girls face.

"As a reality show that has been viewed up to 350 million times on the internet, the program should have done better," Jiang said, urging the show to thoroughly consider its responsibilities.

"Child protection should be the priority when showing the intimacy and 'love' between the 'intern' father-daughter pair," Jiang said.