Shellfish consumed at a Hastings tangi is believed to be linked with cases of paratyphoid being investigated by the Hawke's Bay District Health Board.
it's understood the tangi was for one of two men who fled police and died in Tongariro National Park.
There have been four confirmed cases of paratyphoid fever, all of which have needed hospital trteatment. The health board is following up three suspect cases.
A board spokeswoman said at least two of the cases ate mussels gathered from Napier's Ahuriri area.
There was also concern mussels from the same area may have been eaten at a Tangi at the Tangoio Marae 11 days ago.