Police were aware of domestic disputes between a man and the estranged wife he is suspected of killing, it emerged.
The man is being held on suspicion of killing the woman and her mother in a knife attack.
The suspect, named locally as Sergei Zolotovsky, 42, was allegedly seen standing over the body of Latvian Svetlana Zolotovska in Stansfeld Road, Beckton, east London, holding a kitchen knife yesterday morning. Her throat was cut.
He was then chased to a house in nearby Leamouth Road. It was set on fire and when riot police forced their way inside they found the victim's mother had also been fatally stabbed. The suspect was arrested after being discovered in the loft where he had slashed his neck. He is in a "stable" condition in custody in hospital.
Post mortem examinations have shown the two women died of stab wounds. Police believe the man ambushed his wife after she left home to go to work as a pharmacy technician at the private Wellington Hospital in St John's Wood, north-west London.
Colleagues said the couple were in the middle of a bitter divorce and Mr Zolotovsky had moved into another home a short distance from the scene of the attack.
Her mother, aged in her late 60s or early 70s, moved in three months ago to support her after the couple separated more than a year ago.
A Scotland Yard spokesman said tonight: "We are aware of historic domestic disputes between the victim and her estranged husband. Both the victim and her partner contacted police on four occasions between 2008 and 2009.
"The last contact was in April 2009 when the victim called police to allege her former partner wanted to gain access to the property they had once shared. Police attended and both parties were spoken to.
"Whilst neither party wanted to pursue the matter further Newham's Community Safety Unit contacted the victim at a later date to offer her reassurance and advice on how to keep her property secure."