Masua Tusa, who has cerebral palsy, was reportedly left traumatised by the incident after skin was scraped from his nose, forehead and cheek.
The youngster’s mother refuses to accept the nursery’s claim that her son fell down the stairs while strapped into his wheelchair.
New Zealand police and the Ministry of Education are now investigating the ‘accident’ at the Auckland nursery.
According to Stuff news site, Masau’s mum Milly said: “I’ve asked him a couple of times (about the incident) and all he says is ‘mummy, naughty teacher, mummy, naughty teacher’.
“I thought it (the teacher’s explanation of what happened) was a load of cr*p.
“She told me she was standing in front of him when he fell, if she was standing in front of him, how would she let that happen, if she was supervising him, how did he fall?”
Ms Tusa said it looked more like her son had been dragged – rather than supposedly falling.
She said her boy’s teacher claimed to have called her four times.
The staff member told her she had locked Masua’s wheelchair at the top of the stairs, however it still fell down.
The mother has now removed her son from the nursery, which he is too scared to return to.
Manurewa West Kindergarten declined to be interviewed when approached by Checkpoint radio programme.