Birmingham City Council faces prosecution by health and safety officials over the death of a 92-year-old woman who was crushed by a falling tree in a park.

Daisy Hill was sitting on a park bench in Cannon Hill Park, Moseley, when a 60ft tree fell on her and her carer two years ago. An inquest into Ms Hill's death held in Birmingham a year ago noted there were "clear visible signs" of decay on the tree.

After the hearing, West Midlands Police passed the case over to the Crown Prosecution Service to examine whether criminal proceedings should be brought against the authority.

Lawyers for the CPS concluded there was "no realistic prospect" of a conviction based on "corporate manslaughter" or establishing the culpability of any individuals.

However, the Health and Safety Executive is now examining the case to see whether it can take legal action against the authority.

A spokesman for the HSE based in Birmingham said: "In January, the case was passed onto the HSE to investigate whether there had been any breach of health and safety regulations by the duty holder, Birmingham City Council. That investigation is ongoing."

Lawyers for the HSE are considering whether to prosecute the authority under Section 3 of the Heath and Safety at Work Act 1974.

Ms Hill, from Shard End, died when the 100-year-old beech fell on her and carer Terence McCann, aged 58, on October 12, 2005 while they rested during a stroll in the park.

The inquest heard how Mr McCann had twice got up to investigate after hearing a loud cracking noise. On the second occasion, the sound was described as like "a lorry dumping a load". The tree fell a few minutes later.

A passing police officer found Ms Hill unconscious and Mr McCann fading in and out of consciousness beneath the tree and called for help.

Ms Hill was taken to Selly Oak Hospital but died shortly afterwards of multiple injuries. Mr McCann was treated for back and neck injuries and stress.

A tree expert called to the scene on behalf of the HSE identified 14 trees in the vicinity needing further attention.

The jury at Ms Hill's inquest recorded a narrative verdict and concluded: "The tree fell due to extensive decay in the lower trunk which had been getting worse for several years, weakening the tree until it fell down.

"There would have been clear visible signs on the tree for several years."

At the inquest, HSE investigator David Price also warned: "The case underlines the importance for people who own trees and are responsible for trees in a public area to inspect and maintain them in a safe condition."

Birmingham Coroner Aidan Cotter stressed he would send a letter to Birmingham City Council asking it to confirm if other potentially dangerous trees had been made safe and to confirm future inspections were carried out thoroughly.

A spokesman for the HSE said the investigation could take more than a year before reaching its conclusions.