Les McEwan had defended his department

The council confirmed that Les McEwan, 57, was leaving his post.

The decision comes less than a week after his department was heavily criticised for its handling of the case of 11-week-old Caleb Ness.

Caleb, who was on the child protection register, was killed by his father Alexander, who had a history of violence. His mother, Shirley Malcolm, was a known drug addict.

Alexander Ness was jailed for 11 years for the culpable homicide of his son in October 2001.

A report into the handling of the case found failings at "almost every level" in the agencies involved in the baby's care.

I have been shocked and saddened by the full facts now available in the report into baby Caleb's death Les McEwan

In his resignation letter to council chiefs, Mr McEwan said: "As director, I have ultimate responsibility for everything that happens in the department.

"And as I said at full council, I do not shirk that responsibility.

"I certainly do not in the case of Caleb."

He added: "Having advised the council earlier this year that we needed to give first priority to finding the truth about what happened, I have been shocked and saddened by the full facts now available in the report into baby Caleb's death."

He acknowledged he bore ultimate responsibility as director of the department.

Edinburgh City Council has already announced the suspension of two social workers and the removal of three staff from child protection duties following a review of procedures prompted by the case.

An inquiry by Edinburgh and Lothians Child Protection Committee, chaired by Susan O'Brien QC, concluded that the parents should not have had care of the child and that Caleb's was an "avoidable child death".

Caleb was on the child protection register

The 260-page report directed particular criticism at the city council's social work department and agencies of Lothian Health Board.

However, while it said no single individual should be held responsible, the aftershocks have resulted in consequences for individuals within the council.

Speaking after publication of the report, council leader Donald Anderson said there was a "wave of shock and horror" within the authority.

He described the document as a "devastating report into the childcare procedures".

Edinburgh council chief executive Tom Aitchison, who received Mr McEwan's resignation letter, paid immediate tribute to him.

"It is typical of the man that he is putting the interests of the service before his own," he said.

Mr Aitchison added: "Steps have already been taken to ensure the day to day running of the department following Les' departure."

'Failure of delivery'

Edinburgh council leader Donald Anderson said he had no plans to offer his own resignation.

He told BBC Scotland that politicians would have borne responsibility if the inquiry had criticised council policies or the resources made available for social work.

"But the failure in this case is not about resources, it's not about policies -it's about the way those policies were applied on the ground," he said.

"It's a failure of management and it's a failure of delivery.

"I don't feel it's appropriate to tender my own resignation - if I felt I was culpable in any way, I would."