The Local Government Ombudsman Michael King said York Council poorly handled the case in which supervision arrangements were placed on the parents after injuries were discovered when they took him to hospital with breathing problems in 2016. A doctor noted injuries to his ribs, which the family said could have been caused by treatment during a previous hospital stay.
After nine weeks of hospital care the baby died. During this time the parents had to be supervised at all times when visiting the baby.
The restrictions were not lifted when the baby's condition worsened and meant they were unable to visit on one occasion due to lack of supervision. On other occasions they were only able to spend four hours with their baby. The council required the parents' other two children to be cared for by grandparents.
After the baby's death the court relaxed supervision arrangements relating to the parents' other children and 11 weeks later a court criticised the council's handling of the case, finding that the baby's injuries could not be attributed to parental care.
The ombudsman found that the council had failed to review supervision arrangements for the parents, referred to in the report as Ms X and Mr Y, or offer alternative supervision arrangements through a third party. The council also tried to attribute blame for problems around supervision on the hospital involved.
The ombudsman also found that the care plan in place by social workers did not consider the baby's emotional needs.
"Ms X and Mr Y repeatedly asked the council to review the supervision arrangements to allow them to spend more time with [the baby]," states the report.
"However, the council sought to blame the hospital for refusing to supervise contact. Ultimately it was the council and not the hospital who were responsible for the supervision arrangements being in place.
"The council failed to review its position considering the hospital's response and [the baby's] emotional needs. This is fault."
In addition, the ombudsman is critical of the council's late response to a complaint made by the parents. It took the council almost a year to respond, when the maximum time it should take is 65 days.
"This was a sensitive complaint about issues which had caused Ms X and Mr Y a great deal of distress," states the ombudsman's report.
"There is no evidence in the complaints file that the council recognised this or that any attempts were made to prioritise the complaint even once we became involved."
The council has agreed to apologise to the family and has been ordered to pay them £2,000 for the distress caused.
The council has also agreed to review its policies around supervision arrangements when looked-after children are in hospital and improve its handling of complaints.
"Nobody could criticise the social workers in this case for starting the safeguarding action. But what they should have done was keep the situation under review, especially once it became clear there was very little risk to the child, and his condition deteriorated," said King.
"This would have been a horrifically stressful time for the family, at a time when their world must have felt like it was falling apart. Social workers should have done more to facilitate the parents' visits, for example by contacting social workers in the neighbouring authority, or the hospital's own patient liaison services.
"And to compound this family's distress, the council took far too long to investigate their concerns when they complained about their treatment.
"I'm pleased York Council has accepted the findings of this report, and hope the remedies recommended will prevent other families going through such a distressing situation."
Maxine Squire, York Council's interim corporate director for children, education and communities, said: "We are extremely sorry for the distress caused and have apologised unreservedly to the family.
"We fully accept the ombudsman's findings and recommendations. We have already taken action to ensure that lessons are learned from this case and that our procedures are improved."