The sight of a young child wearing boxing gloves above the caption "Now, No One Can Beat Me!" was designed to “grab people’s attention”, Merton Council said.
The advertisement appeared at various locations in the Broadway in Wimbledon until their removal last week, as part of Merton Council’s campaign to attract more foster families.
But the image was criticised by residents on an internet forum for making light of the issue of child abuse.
A council spokeswoman said: “This campaign was designed to be thought-provoking and attract attention. Whether using a strong image or a play on words we needed to ensure the advert got people looking.”
Last week, Government figures showed Merton was the second worst local authority in the country for getting children through the care system and into an adoptive family.
The spokesman added: “Unfortunately many of Merton’s looked after children have experienced abuse and we wanted to highlight that removing them from this sort of environment and placing them with a foster family can enable them to thrive and develop in a positive way.”