TRAGIC: Dad abandons son, 5, at school after discovering he’s not his father.

A Chinese man refused to care for his son after discovering he’s not actually his biological child.

The 5-year-old, who is being identified under the pseudonym “Xiao Rui,” was abandoned at preschool last week by his father.

According to reports, the father dropped him off for school as usual but failed to return to collect him in the evening.

Xiao had a backpack with him containing only a change of clothes and a mobile phone, reported the Jiangxi Morning Daily via the South China Morning Post.

The boy’s teacher, whom the publications referred to by his surname, Chen, reportedly tried to contact his father.

The father spoke to Chen and refused to pick up the child, stating that he wasn’t the boy’s biological father — according to a paternity test — and that Xiao was now the school’s problem.

Chen visited Xiao’s home later and found it to be empty, and his mother’s whereabouts were unknown.

Local reports said they contacted police, who made contact with Xiao’s grandfather and uncle — but they also allegedly refused to pick the boy up.- NY POST