Police believe the death of a four-year-old girl in her Auckland home earlier this month was not an accident.

Maggie Watson's body was found in an Onehunga house around 4am on Friday the 7th of August.

Experts have carried out a number of tests and police now believe another person, or other people, were involved in her death.

They said they have carried out a considerable number of inquiries over the past three weeks and the investigation is ongoing.