A “COCKTAIL of chemicals” in a blocked drainage system is thought to have severely poisoned three members of staff at a Bournemouth mortuary.

The three council employees remain off sick nearly three months later, having suffered serious side effects.

Holly Tree Lodge in Gloucester Road, Boscombe, remains closed and bodies are still being sent to other parts of the south west.

Council officials say they cannot disclose the nature of the illness because it is personal information, and that tests to establish the cause have been “inconclusive”.

However, a report to the council’s audit and governance committee says the borough has commissioned an external health and safety consultant to examine the building.

It states: “In the consultant’s opinion, the most likely cause of the staff becoming unwell is that they were affected by fumes entering the workroom as a result of the poor design of parts of the drainage system.

“After the incident, the drainage system was examined and as well as observations in relation to the poor design of the waste trap, a blockage was discovered in one of the waste pipes leading to the drain.

“It is likely that the fumes would have resulted from a cocktail of chemicals which are discharged into the drainage system as part of the normal operation of the mortuary.”

Chemicals that would normally be used in a mortuary include a range of dangerous substances. For instance embalming fluid typically contains highly toxic and volatile formaldehyde.

Exposure to formaldehyde vapour can cause burns to the cornea of the eye, the skin and the throat and nasal passages, as well as lung damage, with more severe symptoms including haemorrhage in the gastrointestinal tract.

The chemical is also carcinogenic with chronic exposure, and its industrial use is highly regulated.

A council spokesman said: “There are no firm dates for the staff return or the mortuary to reopen but we are working to ensure that this will be as soon as practically possible.”

It is unclear if any legal action may be taken against the council, either for personal injury or for any breach of regulations.

Modifications to the drainage and ventilation systems are taking place and are expected to end this month.

There is no figure for the costs and the Health and Safety Executive is still investigating.

Lucy Cox, of Winton, lost her mum, 69-year-old Gillian Cox, on February 28.

Ms Cox, 41, told the Daily Echo her family’s loss was made that much harder as a result of the mortuary having closed when no members of staff were able to tell her where her mother’s body was being kept.

“We were told eventually that she’d been taken to Dorchester but we couldn’t make any arrangements,” she said. “It was awful from day one. All we were told was there was a backlog. It got to four-five weeks - it was just ridiculous.”

A service was eventually held for Gillian on March 21.