Families are being warned their relatives may be buried in the wrong place or have the wrong headstone, because burial records in two cemeteries in Berwick were not kept properly.
The "serious errors" happened at North Road Cemetery and Tweedmouth Cemetery over a number of years up to 2009.
The burials were at the time under the responsibility of the old Berwick Borough Council. When Northumberland County Council took over in 2009, it began investigating. Two members of staff have now been dismissed for gross misconduct.
About 30 families may be affected. Some have been told, but others have not yet. The council has set up a helpline for anyone worried and is offering counselling.
There are no plans to move or exhume bodies. In some cases, the council may want to dig down to expose the name plate on top of the coffins, to identify which body is buried in which plot. It says it will work with families to make arrangements.
For more help ring Northumberland County Council between 8am and 8pm on 08444 632330 (or 0203 4170270 for anyone outside the UK).