Armed police descended on a home in Cavendish Road in Sunbury, which is owned by a couple who have fostered hundreds of children.
Penelope and Ronald Jones have been appointed MBEs for services to children and families in 2009.
The Cavendish Road property is registered to Mr and Mrs Jones, 88 and 71, who were honoured by Her Majesty the Queen for their work looking after children.
Officers searched the house from around 1.30pm on Saturday (September 16) in connection with investigations into the terror attack at Parsons Green tube station on Friday (September 15).
They were advised to stay in their properties.
Long time family friend Serena Barber, 45, said that the Joneses had fostered dozens of children.
She said: "Penny's a wonderful foster mother.
"She takes everyone. She doesn't turn anyone away."
The organisation states that Mr and Mrs Jones have been foster parents for almost 40 years and had taken in 268 children.
Some of their foster children include refugees from war-torn countries Iraq, Syria and Afghanistan while they were believed to have been helping Surrey County Council with a scheme relocating Syrian nationals, the Mirror reports.
The council said it was "aware of the reports" but unable to comment because of an active police investigation.
Former neighbour Nikki Nicholass said: "They have always fostered. And amazing at their job.
"They took on troubled kids. They changed kids' lives for the better."
Several residents said the couple lived in the road and Nicola Ryder, who lives opposite, described them as "beautiful people".
She said she knew them just as Penny and Ron, and that they would foster up to seven young people at a time.
An 18-year-old man was arrested by Kent Police in the port area of Dover on Saturday (September 16) under section 41 of the Terrorism Act in connection with the Parsons Green tube station attack.
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