Project Prevention, founded by Barbara Harris, offers cash to drug addicts prepared to accept sterilisation or long term contraception.
It has raised a storm of criticism in the US.
Is Project Prevention little more than eugenics dressed up in a cloak of compassion?
You can watch the full interview on Wednesday 11 August 2010 on the BBC News Channel on BBC World News at 0330, 0830, 1530, 1930 GMT and on the BBC News Channel at 0230 and 0430 BST.
This programme was first broadcast on Tuesday 18 May 2010.