The placement was made before any suspicion of terrorist activity arose and the child was removed as soon as police alerted the council.
Abdulla Ahmed Ali, ringleader of the plot to blow up seven airliners, was convicted along with two other men on Monday.
The foster child was placed with his relatives in a house where he also lived before he was arrested in 2006.
A Haringey spokeswoman said: "The placement here was made after checks and before anyone was made aware of any terrorist activity in the extended family network.
"The child was moved immediately when the police were in touch and arrests were made in 2006. The family no longer fosters for Haringey."
Meanwhile the three people convicted of causing Baby Peter 's death in Haringey have been refused leave to appeal against their sentences. In May, Baby Peter's mother was handed a minimum sentence of five years for causing or allowing his death. Her lodger, who was convicted of the same offence, must serve three years.
The mother's boyfriend, who is also serving a life term after being convicted of raping a two-year-old girl, was given a minimum term of 10 years for his part in Peter's death.
