Thirty bodies may have been buried in the wrong graves at Berwick and Tweedmouth cemeteries because of mistakes dating back a number of years prior to 2009.
The issue came to light after an independent investigation found historical inaccuracies in the records of the North Road and Cemetery Loaning sites.
Northumberland County Council commissioned the investigation, as well as implementing internal disciplinary procedures, after suspecting a problem when it took over responsibility for the cemeteries from Berwick Borough Council three years ago.
Two members of staff were suspended and subsequently dismissed.
Known mistakes include burials in the wrong plots, memorials on the wrong grave, deeds issued incorrectly, and unregistered burials.
At present, it is thought that most of the errors can be corrected simply by clarifying details in the burial records.
In a very small number of cases, however, the county council has revealed that more detailed investigation is required which could include partial excavation. In these cases, the authority has stressed it will work very closely with families and take any action only with their approval and express permission.
Steps are already being taken to contact any families who may be affected.
Roger Styring, the council’s deputy leader, said: “We understand that this could be extremely upsetting for people affected by this and we’re sorry for the distress caused.
“We are making a commitment to all of the families involved that we will deal with these issues in an extremely sensitive manner and would like to reassure people that we are working with the greatest of care, respect and sensitivity, and our sympathies are with anyone who is involved.
“We are putting support in place to ensure that anyone affected has full knowledge and any support and guidance that they need during the work.”
The council says systems and procedures at the cemeteries have been fully reviewed and that all the correct processes are now in place to ensure that no such problems arise in the future.
A telephone hotline has been set up for those with any concerns and people are urged to call 08444 632330.