Poweshell SharePoint BypassLocks attempting to perform an unauthorised operation

I get the following error when I try to run:

Powershell ByPassLocks

Exception calling "BypassLocks" with 2 argument(s) attempting to perform an unauthorized operation.

I am just wondering how I can resolve this?

           $recordsmanagement=[Microsoft.Office.RecordsManagement.RecordsRepository.Records]

                          $ChangeRecord = {
                          param( [Microsoft.SharePoint.SPListItem] $listItem)
                          $MMSField.SetFieldValue($listItem,$spTerm); 
                          $listitem.SystemUpdate() 
                       }

                        #pass the delegate to the By Pass locks API
                        $recordsmanagement::bypasslocks($listItem, $ChangeRecord)

Any idea how this can be resolved?                 

faye fouladi