A forensic pathologist giving evidence at an inquest into the death a father and his two sons say the cause of the children's death was "un-ascertained."
Amanda Jeffrey told the court both boys had the sleeping drug Zopiclone in their blood stream.
11 year old Jack had a relatively small amount but 3 year old Bryn had a higher dose that may have killed him. She said Jack may have been smothered.
Their father, Graham Anderson, was found with a neck injury and a belt around his neck.
More top news
The RSPCA is investigating after a pet cat was fatally injured after being shot by someone using an airgun on Christmas Eve.
Bristol City manager Lee Johnson has further bolstered his first team squad by bringing in German goalkeeper Fabian Giefer from Schalke.
There were a series of burglaries to homes in South Gloucestershire on Tuesday (17/01) - police believe they are all linked.