A judge has not minced his words when describing the actions of a former Northland educator and church leader convicted of dozens of sex crimes against young girls.

"You are a paedophile," said Judge Duncan Harvey.

"You have absolutely no remorse, you do not accept your offending and you are a high risk to others."

James Sanders, 68, was found guilty in February on 35 charges relating to 13 different victims, with his youngest victim being just six-years-old.

Saunders' offending began when he was the leader of a Mormon church south of Whangarei.

Source: 1 NEWS

It continued at a Northland school where he helped his wife run an after school care centre.

Today, he was sentenced at the Whangarei District Court to 20 years in jail.

It can also be revealed Sanders was investigated on three other occasions in the 1980s, 1990 and then again in 2003.

They were documented, but the school where Sanders volunteered never knew, because police checks came back clear.

Ruth Money, a victims' advocate, says that's not good enough.

"This school did everything right, they tried to protect their community and a vetting system is supposed to do just that.

"It provided nothing but nonsense and here we have abused children as a result of that."

Police say they have to be very careful about releasing information about a person when they have not been convicted.