Brass fittings are the key source of lead leaching at the Perth Children's Hospital, rather than the "dead leg" in the ring main, the state government says.

The West Australian government has released a technical report into the ongoing issue, partly disputing the findings of an independent report from the Building Commission last month, which found the most likely source of contamination was both the ring main pipes and the brass fittings. Treasurer Ben Wyatt said the…