A depressed pregnant mother cut the throats of her three children before pleading with police to shoot her, a court was told.

Sasikala Navaneethan stabbed and slit the throats of her son Shanjayan, five, daughter Sharani, four, and her six-month-old baby girl Trishana last year at her Carshalton home.

She said she was driven to it by voices in her head, who convinced her that her husband Navarajah, who owned and worked in a convenience store in Coulsdon, was having an affair and beating her, the Old Bailey heard.

Appearing on Monday, Navaneethan, 37, pleaded guilty to two charges of manslaughter on the grounds of diminished responsibility.

She also pleaded guilty to the attempted murder of baby Trishana.

The court heard how on May 30 last year Navaneethan said the voices in her head, which had suggested killing her children every day for the past month, came back and this time she acted.

She stabbed and slit the throats of her three children before lining them up in their beds at their Carshalton home.

Navaneethan called the police saying she had killed her children.

When they arrived, Navaneethan said she had put the knife under the bed.

When they searched they found three knives, along with a discarded necklace her husband had given to her to signify their marriage, and a letter.

The note accused her husband of having a “clandestine affair with two persons”.

It also contained sentences such as “I screamed in tears”, “no one has helped me”, and “it is better if we all die”.

As police arrested her she asked: “Can you murder me, I don’t want to live anymore.”

She said she had taken rat poison and some “red tablets” as she tried to take her own life.

The court heard how she was deeply affected by the civil war in her home country of Sri Lanka, which she left for England in 1999, and had nightmares and flashbacks.

There was unanimity from three doctors that she was suffering from a mental disorder.

David Etherington QC, defending, said “cultural expectations” may have resulted in Navaneethan showing physical injuries to her GP rather than revealing her mental problems.

“She believed there was no point in life any longer and felt she could not leave the children with her husband.”

He added: “She now has the unbearable horror of knowing what she has done.

“She was a very sick woman and still is a very sick woman."

Judge Brian Barker, presiding, said: “This is a profoundly sad and tragic case.

“You believed at the time you and your children were better off dead.

“You had concerns about the family finances, infidelity, domestic abuse and social isolation.

“Your turmoil and actions are virtually impossible for a person on the outside to understand.”

He praised the work of paramedics to save the life of Trishana, who is unlikely to have any long-term damage from the attack.

She, along with Navaneethan’s fourth child who was born in January, are likely to stay with the father.

Navaneethan was committed to a psychiatric hospital indefinitely.

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