Usha Patel was found dead in her Cricklewood flat in northwest London, where she lived with her five-year-old autistic son.
The Metropolitan Police have said they are on the hunt for Miles Donnelly, 34, who is believed to have met the victim online.
Donnelly, who is described as a white man about 5 feet 11 inches tall with his last known address in Paddington in west London is believed to visit a number of London boroughs.
"I would appeal directly to him to contact the police so that we can speak to him. It is possible that he will look to friends and associates for support, and I urge them not to get involved but to contact us instead. I would like to reassure anyone who is worried about contacting the police that they will be treated with the utmost sensitivity."
Patel's neighbours said she had lived at the property for about nine years.
A Scotland Yard spokesperson has appealed people not to approach Donnely if they have seen him, but to inform them instead.
