He said the police have an independent complaints authority - the Independent Police Conduct Authority (IPCA) and this was the type of watchdog needed for Oranga Tamariki.
"Both the Greens and NZ First support an independent agency with the Greens rightly saying that there is a lot of potential for things to go wrong in child protection and, just like the police, there really does need to be independent oversight."
But he said the success of any complaints authority would depend on its independence.
"It must have legislative independence, operational independence, and the perception of independence, similar to the IPCA."
Mr McCoskrie said it would also be in the best interest of social workers because it would provide an independent body to ensure appropriate policy and procedures have been followed.
"This will result in public confidence and accountability for actions and decisions by social workers."
A poll in 2011 found 65 per cent supported the need for an independent watchdog for Child Youth and Family, while 20 per cent were opposed.
The Masieys' story has created a social media storm on Facebook with people appalled with the treatment this Whanganui family received.
Helena Allen said: A gross misconduct of judgmental Justice. This is an absolute travesty. What happened to these agencies working towards supporting keeping families together? All this does is stops struggling young families from wanting agencies who are meant to be there to provide support after child birth from entering their homes! Disgusting.
Layce Madams said: So sad that this family had to go through that trauma.
Amina Ahmad said: Some social workers need to look at other cases where children in care are sent to school in their pyjamas and with no breakfast all because they didn't get ready in time how sad is that.
Tina Hart said: It's Wanganui, and unfortunately there are people that think they're above the law and think they know it when in reality they don't and cause a lot of families hurt and stress and don't think about the effect it has on the kids.