Boyd faces a charge of assaulting her 23-month-old son Brandon Muir on March 5 last year at the Douglas Family Centre, Balmerino Road, by striking him on the leg to his injury.

She also denies that, on March 15 or 16, at addresses in Balunie Crescent, she failed to ensure Brandon’s well-being and failed to seek any medical treatment for his injuries, as a consequence of which, Brandon was caused unnecessary suffering and injury and was so severely injured he died on March 16 at Ninewells Hospital, and she killed him.

Robert Cunningham, as someone who had charge of care of the child, Brandon Muir, now deceased, denies he assaulted Brandon by seizing hold of him by the body, forcing him to stand against a wall or other surface, applying pressure to his abdomen by unknown means and then failed to seek any medical treatment for him, whereby he was so severely injured he later died on March 16 and he murdered him.

Cunningham also denies that on various occasions between October 1, 2007 and March 16 last year, at three addresses in Dundee and elsewhere, he repeatedly and wilfully ill-treated Brandon in a manner likely to cause him unnecessary suffering or injury to health and he used or allowed others to use the controlled drugs, cannabis and diamorphine, seized hold of Brandon by the arm, shouted and swore at him, subjected him to excessive noise, struck him on the head and body, seized hold of and compressed his body and forced him to assume a sitting or standing position for prolonged periods, all to his severe injury and distress.

He further denies that on various occasions between October 25, 2007 and March 14 last year, he wilfully ill-treated another child.

The first witness, Grant Thomson (39), a crime scene examiner from the Scottish Police Services Authority in Dundee, said he was asked to take photographs of the layout of a flat at Balunie Crescent on March 16.

Jurors were shown photographs of the front door and the hallway inside the flat leading to a living room at the end of the corridor.

Mr Thomson said photographs of a bedroom which was the first door on the left after entering showed child’s toys under a window, a child’s bicycle in the corner of the room, a drying screen in front of a radiator and other items of furniture.

Immediately opposite, was another bedroom, he told Advocate Depute James Wolffe QC.

Detailed pictures showed a bed in the room and an ashtray on the bed.

Donald Findlay QC appears for Boyd and Cunningham is represented by Ian Duguid QC.

The trial continues before temporary judge John Morris QC and a jury.