A Toronto-area woman who was seeking treatment for post-partum depression is in police custody in Britain in connection with the death of her two children.
Neither Canadian officials nor London police would release the woman's name, but British media reports have identified her as 34-year-old Felicia Boots.
Reports say her husband, Jeffrey Boots, a former investment banker with the Bank of Montreal, discovered the bodies of the children on Wednesday night.
London police say the victims were a 10-week-old boy and a 14-month-old girl, but would not speculate on their identities or cause of death.
A police news release says a woman is being held on suspicion of murder and a spokesman says investigators are not seeking any other suspects.
Clare Delpech of Britain's Association of Post-Natal Illness told CBC's Susan Ormiston Friday that Boots was a client of her organization.
Delpech said Boots had requested email support, in which a volunteer would email her at regular intervals to see how she was feeling.
"She felt very isolated after she had her first baby," said Delpech, who has spoken to a colleague who was in contact with Boots. "She felt unwell and didn't find it easy to get out and be sociable. It seemed that isolation was one of the things she brought up repeatedly."
Delpech said Boots had declined phone support and that volunteers at her organization had no sense that she was getting worse.
"The actual act of killing a child is very rare in cases of depression, said Delpech. "You can only feel sorry for the whole family. It's such a tragedy."
The Daily Telegraph described the woman as a "wealthy investment banker's wife," saying she and her husband had just moved into a $1.9-million home in Wandsworth, South London.
Neighbours said the couple, both originally from Canada, had moved into the five-bedroom house two weeks ago after the birth of their second child, and they seemed happy and excited about the future, the paper reported on its website. On Wednesday evening, Jeffrey Boots was heard wailing in the street, shortly before an ambulance and police cars arrived on the scene.
Autopsies were scheduled for Friday morning. Police say they would release more details at that time.
Felicia Boots was described in London media reports as a jewelry designer and former hairstylist who was pursuing her craft there.
Jeffrey Boots left the Bank of Montreal last year, the paper said, but his current occupation wasn't immediately clear. Until recently, the couple had rented a two-bedroom penthouse apartment in nearby Wandsworth Town for about $3,400 a month, the Telegraph reported. but completed their new family property just last month, weeks after the birth of their second child.