Teepu couldn't be contacted this afternoon, but wrote on Facebook: "Amy pepper sprayed because they missed Blue in the driver's seat shot Amy in the back of the truck".
In response to a question from a friend about how Amy was doing, Teepu wrote: "Burnt face contact lenses hooked to her to help wash with hospital water??? Go to optometrists in the a.m."
Bay of Plenty district commander superintendent Andy McGregor said the girl was "accidently contaminated with pepper spray" just after 5.30pm while a passenger in a vehicle where a man was allegedly resisting arrest.
Police said the man was being violent and he has since been charged with serious assault.
It unfolded as the man was at the centre of an incident during a routine traffic stop, McGregor said.
Police said the man refused to give his details and tried to drive off.
The officer attempted to remove the keys but his arm was allegedly trapped when the man wound the window up.
"As the officer pulled his arm free, the window broke, causing minor cuts. Unfortunately during the arrest, a girl who was in the car with the man was accidentally contaminated by some of the spray."
Police provided immediate care for the child and she suffered "no lasting injury".
"We're sorry for the obvious distress and pain this would have caused the girl during the incident and are pleased she is okay. However, had it not been for the actions of the man involved, officers would not have had to use pepper spray.
"It is also sad that she is an innocent victim who has had to witness this incident, which could have been completely avoided."
The police officer received minor injuries and has returned to duty.
A police spokesman said the man was now facing two charges of aggravated assault, and one charge each of failing to stop, and giving false details.
Teepu's post provoked an angry reaction on Facebook. It had been shared almost 300 times by mid-afternoon.
Sallyanne Mason commented that the alleged incident was inhumane.
"To think that not even a grown man can handle being peppered sprayed, but to frickn spray an innocent 10-year-old girl who is still in primary school is not even fricken humane!!!!!"
Linda Akuhata wrote that she was "speechless".
"Hope she is all right."