diff --git a/app/models/event.rb b/app/models/event.rb
index dbd02bb52..6df5527de 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -532,6 +532,48 @@ def access_method
     end
   end
 
+  def self.subj_id_check(options = {})
+    file_name = "evens_with_double_crossref_dois.txt"
+    size = (options[:size] || 1000).to_i
+    cursor = [options[:from_id], options[:until_id]]
+    total_errors = 0
+
+    response = Event.query(nil, source_id: "datacite-crossref,datacite-related", page: { size: 1, cursor: [] })
+    Rails.logger.info "[DoubleCheck] #{response.results.total} events for source datacite-crossref,datacite-related."
+
+    # walk through results using cursor
+    if response.results.total.positive?
+      while response.results.results.length.positive?
+        response = Event.query(nil, source_id: "datacite-crossref,datacite-related", page: { size: size, cursor: cursor })
+        break unless response.results.results.length.positive?
+
+        Rails.logger.info "[DoubleCheck] DoubleCheck #{response.results.results.length}  events starting with _id #{response.results.to_a.first[:_id]}."
+        cursor = response.results.to_a.last[:sort]
+
+        # dois = response.results.results.map(&:subj_id)
+        events = response.results.results
+        events.lazy.each do | event|
+          subj_prefix = event.subj_id[/(10\.\d{4,5})/, 1]
+          if Prefix.where(prefix: subj_prefix).empty?
+            File.open(file_name, "a+") do |f|
+              f.write(event.uuid, "\n")
+              total_errors = total_errors + 1
+            end
+          end
+        end
+      end
+    end
+
+    file = File.open(file_name)
+    if file.present?
+      payload = { description: "events_with_errors_from_rake_task #{Time.now.getutc}", public: true,files: {uids_with_errors: {content: file.read} }}
+      ### max file size 1MB
+      response = Maremma.post("https://api.github.com/gists", data: payload.to_json, username: ENV["GIST_USERNAME"], password:ENV["GIST_PASSWORD"])
+      Rails.logger.warn "[DoubleCheck] Total number of events with Errors: #{total_errors}"
+      Rails.logger.warn "[DoubleCheck] IDs saved: #{response.body.dig('data','url')}" if [200,201].include?(response.status)
+    end
+  end
+
   def metric_type
     if relation_type_id.to_s =~ /(requests|investigations)/
       arr = relation_type_id.split("-", 4)
diff --git a/lib/tasks/event.rake b/lib/tasks/event.rake
index 2271b7018..63f052a04 100644
--- a/lib/tasks/event.rake
+++ b/lib/tasks/event.rake
@@ -78,6 +78,16 @@ namespace :crossref do
   end
 end
 
+namespace :subj_id_check do
+  desc 'checks that events subject node congruency'
+  task :check => :environment do
+    from_id = (ENV['FROM_ID'] || Event.minimum(:id)).to_i
+    until_id = (ENV['UNTIL_ID'] || Event.maximum(:id)).to_i
+    
+    Event.subj_id_check(from_id: from_id, until_id: until_id)
+  end
+end
+
 namespace :datacite_crossref do
   desc 'Import crossref dois for all events'
   task :import_doi => :environment do
diff --git a/spec/models/event_spec.rb b/spec/models/event_spec.rb
index f94b8744d..0ddd279f2 100644
--- a/spec/models/event_spec.rb
+++ b/spec/models/event_spec.rb
@@ -37,5 +37,27 @@
       expect(published).to eq("2011")
       expect(published).not_to eq(2011)
     end
+
+    # context "double_crossref_check", elasticsearch: true do
+    #   let(:provider) { create(:provider, symbol: "DATACITE") }
+    #   let(:client) { create(:client, provider: provider, symbol: ENV['MDS_USERNAME'], password: ENV['MDS_PASSWORD']) }
+    #   let!(:prefix) { create(:prefix, prefix: "10.14454") }
+    #   let!(:client_prefix) { create(:client_prefix, client: client, prefix: prefix) }
+    #   let!(:doi) { create(:doi, client: client) }
+    #   let!(:dois)  { create_list(:doi, 10) }
+    #   let!(:events) { create_list(:event_for_datacite_related, 30, source_id: "datacite-crossref", obj_id: doi.doi) }
+ 
+    #   before do
+    #     Provider.import
+    #     Client.import
+    #     Doi.import
+    #     Event.import
+    #     sleep 3
+    #   end
+      
+    #   it "check run" do
+    #     expect(Event.subj_id_check(cursor: [Event.minimum(:id),Event.maximum(:id)])).to eq(true)
+    #   end
+    # end
   end
 end