No identities yet after ACT fire deaths

Police are waiting for toxicology reports before confirming the identities of three people killed in a deliberately lit house fire in Canberra.

No family members have been notified of the deaths, despite autopsies being done after Monday's blaze.

Neighbours have told the Nine Network a mother lived at the Bonner property and that her two children visited on weekends.

Police described the investigation as "extremely complex".

"There are a large number of investigative avenues currently being examined to assist in determining the circumstances that led to this tragic outcome," they said.

A man was questioned by police on Tuesday and released without charge.

Forensic investigators at the scene on Tuesday confirmed the use of accelerants and identified a number of different starting points for the fire.

Investigators have not confirmed whether the victims were adults or children, or where in the home the bodies were discovered.