A baby boy starved to death surrounded by soiled nappies and mouldy food in a “filthy” St John’s Wood flat after his mother contracted a rare condition related to HIV that left her unable to care for him.

The 11-month-old, who can only be named as Baby EG for legal reasons, was found dead in his cot with plates of dry cereal that his three-year-old sister had tried to feed to him.

His mother, who also cannot be named, was arrested on suspicion of neglect but died two days later while still in police custody from a rare brain condition associated with HIV.

Paramedics, who found Baby EG’s body after being alerted by a 999 call from the mother on March 8, 2010, said the room “looked like somebody had emptied a bin liner on the floor”.

Westminster Coroner’s Court heard last Thursday that Baby EG’s three-year-old sister “had the run of the flat for the last few days” and had been left to fend for herself and her baby brother.

A post-mortem found Baby EG had starved to death and his stomach was completely empty.

The mother, originally from Africa, was arrested but quickly taken to hospital where she was admitted to the high dependency unit. She told doctors she had not eaten for two days.

She was found to have encephalitis – swelling of the brain – associated with her HIV. Her condition deteriorated rapidly and she died on March 10, 2010.

Social workers and health professionals had been in touch with the family for years leading up to the deaths.

But the court heard they had no concerns about the 29-year-old mother’s care of her two children.

A paediatric physiotherapist, who cannot be named, was the last medical professional to see the family before the tragic events. She told the court that when she saw them on March 1 there were no signs of what was to happen later that week.

She said that when she assessed Baby EG he had “beautiful skin” and was “immaculate”. The mother was “very proud of her children” and despite appearing low in mood, she was responsive and asked insightful questions.

Shedding tears, the physiotherapist said she had been “horrified and shocked” to hear of the baby’s death seven days after her visit and that of his mother two days later.

“I have played this back and forth for two years, saying could something have been done differently,” she said. “I don’t think so.”

Independent consultant Guy Baily told the court it was likely that the mother’s illness would have prevented her from caring for her children.

A jury found that Baby EG had died as a result of an accident while his mother had died from natural causes.