Police are treating the death of local boy Kane Morris as murder.
The 10-year-old died at an address in Coupar Angus on Sunday morning following an incident.
An eight-year-old girl was also found at the property with serious injuries. She remains in a critical condition in Ninewells Hospital.
A 37-year-old man remains under police arrest in connection with the incident.
As investigations into Kane’s murder continue, officers are looking to speak with two men who are believed to have passed the property on Union Street at the time.
Detective Inspector Ross Fitzgerald from the Major Investigation Team said: “We believe the two men may have heard a disturbance at around 2:05am on Union Street on Sunday and would urge them to speak to us.
“Our inquiries remain ongoing in order for us to establish the full circumstances of what happened and we continue to urge anyone who hasn’t spoken to us already to do so.
“A 37-year-old man remains under arrest in connection with the incident.
“An 8-year-old girl who was also injured during the incident remains in a critical but stable condition in hospital.
“Local officers will also be in the community conducting additional patrols over the next few days as our investigation continues.
“Anyone with information is asked to contact Police Scotland on 101 quoting incident 611 of 11 November. If you wish to remain anonymous, you can contact the independent charity Crimestoppers on 0800 555 111.”