Dr Muzaffar Ghanghro has been charged with negligence and manslaughter.
One parent said he saw the paediatrician rummaging through a bin for a needle.
Health officials fear the number of infected could be much higher.
Dr Muzaffar Ghanghro allegedly used infected syringes on children.
Nearly 900 children in a Pakistani city have tested positive for HIV after a rogue doctor reused infected syringes.
Earlier this year, it was reported that there had been an outbreak of 500 cases of the virus in Ratodero.
But now the figure is as high as 1,100, with 900 children, with health officials fearing hundreds more, after paediatrician Dr Muzaffar Ghanghro allegedly used infected syringes.
The doctor was charging 16p a visit and was one of the cheapest in the city.
A quarter of the city’s 200,000 residents have been tested so far, leading health officials to fear the number could be much higher, according to The New York Times.
He was later arrested and charged with negligence and manslaughter after the scale of the outbreak came out.
Dr Ghanghro has not yet been convicted and is still working as a GP at a public hospital on the city’s outskirts.
The lack of awareness about HIV has led to some of the 900 infected children being shunned by their friends and being forced to sit alone.