A mentally ill man who gouged out his grandmother's eyes and killed the family pets following release from hospital has been locked up indefinitely.

Kordian Filmanowicz, 21, stabbed and slashed 62-year-old Ilona Czuper more than 60 times and smashed her skull with a paving slab during the "frenzied and vicious" attack.

He went on to crush the heads of a cat and dog before calmly walking away from the home in Mitcham.

The paranoid schizophrenic admitted manslaughter on the grounds of diminished responsibility at the Old Bailey.

The court heard how the defendant had a "fixation" with eyes, believing they "represented the demons of those behind them", and thought he was Jesus.

He had spent six months in psychiatric hospitals but was released on May 8, 2017, about two months before the brutal killings in Edgehill Road on July 6.

During his stay at a unit in Croydon, he threatened a staff member "in an aggressive way" with a plastic teaspoon by saying he would remove her eyes with it.

But senior psychiatrists released him into the community on medication after deciding he had made a "huge improvement" and his delusional thoughts were "less intrusive."

The family had moved into the area covered by the South West London and St George's Mental Health NHS Trust and visits by mental health teams "certainly slowed down" as a result, prosecutor James Mulholland QC said.

However, Filmanowicz quickly deteriorated, stopped taking his medication and threatened the dog with a rock, believing it was possessed by a demon, the court heard.

The trust assessed him at home but he refused voluntary hospital admission so a full assessment was to be scheduled, the court was told.

"It will appear from notes no assessment could be arranged for the period between June 23 and Ms Czuper's death," said Mr Mulholland.

The Polish national's mother and sister returned home from work to find a trail of blood leading to their garden.

In a victim impact statement, Filmanowicz's mother Marta said the family was "destroyed" by his illness, but insisted she "did not give birth to a murderer."

Judge Anthony Leonard QC told the defendant: "She says nothing can get her mother back but she asks for help in getting you back by getting you the right treatment."

He handed Filmanowicz a hospital order in a secure unit without limit of time.

The judge said he would be surprised if the defendant was deemed fit to be released in under 10 years.

And he advised against medical experts taking his progress at face value, saying they should take great care "bearing in mind the decisions taken in the months leading up to his offending."