??A post mortem examination will be conducted to determine the cause of death. However initial inquiries suggest there are no suspicious circumstances,?? the police spokesman said.
Ferguson served 14 years in jail in Queensland for the abduction and sexual assault of three children - aged six, seven and eight - in a Brisbane motel in 1987.
Ferguson and his then male lover, Alexandria George Brookes, abducted two boys and a girl from Sydney and flew them to Brisbane in July 1987.
The children were sexually abused in a motel in the inner Brisbane suburb of Ascot. Police arrested the pair at the motel, and Ferguson and Brookes were convicted by a Queensland court the same year.
Ferguson was released from prison in 1999.
He had been living in an undisclosed location in Sydney since 2009, when residents in Ryde had discovered the registered sex offender had been given a five-year public housing lease in their suburb.
When Ferguson publicly said he would only leave his unit in a "pine box", a neighbour put a replica coffin outside his front door and a campaign was launched to have him evicted.
Legislation allowing Housing NSW to terminate the public housing leases of registered child-sex offenders passed through Parliament in response to the controversy surrounding Ferguson. The NSW Government cancelled Ferguson?s public housing lease following a recommendation by NSW Police Commissioner Andrew Scipione.
At the time, Ferguson said he posed no threat to children in the general community, but would consider chemical castration if it was deemed safe and effective.
In an interview with the ABC, Ferguson said people who were sexually attracted to children, over time lost interest in them.
??Myself? Children don?t bother me,?? Ferguson said.
??I?m no longer interested.??
In 2009, Ferguson also was spotted in the change rooms of an inner-city Sydney pool and photographed at Coogee Beach with children in the background.
At the time, NSW Police lodged an interim order to restrict Ferguson?s movements. Ferguson later agreed to a set of terms with NSW Police that limited his access to children.
He could not approach children under 14 years, seek paid or voluntary work that would see him in contact with children under 14 or participate or seek to mind or care for a person under the age of 16 years, unless given prior approval by the child protection register.
Hetty Johnston, the chief executive and founder of child advocacy group Bravehearts, said she felt no sadness at the death of Ferguson.
??2013 is going to be a safer place without Dennis Ferguson,?? she said.
??I honestly have to say that I didn?t feel much really at all, just relief I guess, that for his victims at least he is no longer here. It?s a little bit of closure for them. The damage he caused to his victims was just horrendous. It?s unforgivable what he did.
??I can honestly say I don?t feel any sadness at all at his departure.
??People won?t have to stop and look over their shoulders as to where this guy?s living.??