In a letter to Hackney chief executive Tony Elliston, Liberal Democrat deputy group leader Keith Steventon expressed concern that the council has so far managed to contact only around 70 of the 415 young people who came into contact with Mark Trotter until he retired on ill- health grounds in 1993.
Of those traced, four are now dead. Two were killed in accidents, one committed suicide and one died of Aids. The National Society for the Prevention of Cruelty to Children has since taken on the search.
The Liberal Democrats have now secured a special council meeting at which they will call for an independent inquiry to examine the recruitment and activities of Mr Trotter and how Hackney investigated claims made against him during and after his employment.
The move follows claims that Hackney failed to handle the Trotter affair properly when, a month after his death in July 1995, it emerged that he had abused children in Liverpool.
The council is under fire for appointing a social work manager who was serving his notice to prepare a report on Mr Trotter and trace the children.
Len Redley was asked to report back by December 1995. The deadline was extended to February 1996, the date he left the council's employment, but the report was not received until last month.
A Hackney spokeswoman said Mr Elliston and Ms Moseley were looking into criticisms concerning the delay and the substance of the report, but she insisted that Mr Redley was an experienced social worker with detailed knowledge of the care system in Hackney.
Mr Elliston said: 'I have every confidence in the professionalism of senior officers in social services and have found no evidence to suggest that this confidence is misplaced. But I am seriously concerned about allegations of mismanagement and a cover up and I am obviously considering a full independent investigation, while taking advice from the appropriate agencies.'
Ms Moseley said: 'While I understand the instinctive response is to call for suspensions, I am confident we have acted quickly and appropriately in managing this difficult situation.'