Public Health England (PHE) has revealed that chicken liver parfait was the cause of illness at Brockley Hall Hotel in Saltburn.
Most of those who fell ill had been attending a 40th birthday celebration on Friday, July 7 – with three of them being hospitalised.
This included the birthday girl herself, who ended up in hospital on a drip.
A spokeswoman for PHE said their investigation is now complete , and that a copy of the outbreak report has been sent to Redcar and Cleveland Council.
The decision on what further action, if any, to take rests with the local authority .