diff --git a/lib/pact_broker/db/clean.rb b/lib/pact_broker/db/clean.rb
new file mode 100644
index 000000000..dfc8e1316
--- /dev/null
+++ b/lib/pact_broker/db/clean.rb
@@ -0,0 +1,49 @@
+require 'sequel'
+require 'pact_broker/project_root'
+
+module PactBroker
+  module DB
+    class Clean
+      def self.call database_connection, options = {}
+        new(database_connection, options).call
+      end
+
+      def initialize database_connection, options = {}
+        @db = database_connection
+        @options = options
+      end
+
+      def call
+        db[:verifications].where(id: db[:materialized_head_matrix].select(:verification_id)).invert.delete
+        pp_ids = db[:materialized_head_matrix].select(:pact_publication_id)
+
+        triggered_webhook_ids = db[:triggered_webhooks].where(pact_publication_id: pp_ids).invert.select(:id)
+        db[:webhook_executions].where(triggered_webhook_id: triggered_webhook_ids).delete
+        db[:triggered_webhooks].where(id: triggered_webhook_ids).delete
+        db[:webhook_executions].where(pact_publication_id: pp_ids).invert.delete
+
+        db[:pact_publications].where(id: pp_ids).invert.delete
+
+        referenced_pact_version_ids = db[:pact_publications].select(:pact_version_id).collect{ | h| h[:pact_version_id] } +
+          db[:verifications].select(:pact_version_id).collect{ | h| h[:pact_version_id] }
+        db[:pact_versions].where(id: referenced_pact_version_ids).invert.delete
+
+        referenced_version_ids = db[:pact_publications].select(:consumer_version_id).collect{ | h| h[:consumer_version_id] } +
+          db[:verifications].select(:provider_version_id).collect{ | h| h[:provider_version_id] }
+
+        db[:tags].where(version_id: referenced_version_ids).invert.delete
+        db[:versions].where(id: referenced_version_ids).invert.delete
+
+        db[:materialized_matrix].delete
+        db[:materialized_matrix].insert(db[:matrix].select_all)
+        db[:materialized_head_matrix].delete
+        db[:materialized_head_matrix].insert(db[:head_matrix].select_all)
+      end
+
+      private
+
+      attr_reader :db
+
+    end
+  end
+end
diff --git a/lib/pact_broker/tasks.rb b/lib/pact_broker/tasks.rb
index 24741e128..42b6e608e 100644
--- a/lib/pact_broker/tasks.rb
+++ b/lib/pact_broker/tasks.rb
@@ -1,2 +1,3 @@
 require 'pact_broker/tasks/migration_task'
 require 'pact_broker/tasks/version_task'
+require 'pact_broker/tasks/clean_task'
diff --git a/lib/pact_broker/tasks/clean_task.rb b/lib/pact_broker/tasks/clean_task.rb
new file mode 100644
index 000000000..d93639d99
--- /dev/null
+++ b/lib/pact_broker/tasks/clean_task.rb
@@ -0,0 +1,25 @@
+module PactBroker
+  module DB
+    class CleanTask < ::Rake::TaskLib
+
+      attr_accessor :database_connection
+
+      def initialize &block
+        rake_task &block
+      end
+
+      def rake_task &block
+        namespace :pact_broker do
+          namespace :db do
+            desc "Clean unused pacts and verifications from database"
+            task :clean do | t, args |
+              require 'pact_broker/db/clean'
+              instance_eval(&block)
+              PactBroker::DB::Clean.call(database_connection)
+            end
+          end
+        end
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/spec/lib/pact_broker/db/clean_spec.rb b/spec/lib/pact_broker/db/clean_spec.rb
new file mode 100644
index 000000000..000adab05
--- /dev/null
+++ b/spec/lib/pact_broker/db/clean_spec.rb
@@ -0,0 +1,62 @@
+require 'pact_broker/db/clean'
+
+module PactBroker
+  module DB
+    describe Clean do
+      describe ".call" do
+
+        let(:td) { TestDataBuilder.new }
+        before do
+          td.create_pact_with_hierarchy("Foo", "0", "Bar")
+            .create_consumer_version_tag("prod")
+            .create_consumer_version("1")
+            .create_pact
+            .create_consumer_version_tag("prod")
+            .comment("keep")
+            .create_verification(provider_version: "20")
+            .create_consumer_version("2")
+            .create_pact
+            .comment("don't keep")
+            .create_webhook
+            .create_triggered_webhook
+            .create_webhook_execution
+            .create_deprecated_webhook_execution
+            .create_verification(provider_version: "30")
+            .create_consumer_version("3")
+            .create_pact
+            .comment("keep")
+            .create_verification(provider_version: "40")
+            .create_verification(provider_version: "50", number: 2)
+        end
+
+        subject { Clean.call(PactBroker::DB.connection) }
+        let(:db) { PactBroker::DB.connection }
+
+        it "does not delete any rows in the head matrix" do
+          head_matrix_before = db[:head_matrix].select_all
+          subject
+          head_matrix_after = db[:head_matrix].select_all
+          expect(head_matrix_before).to eq head_matrix_after
+        end
+
+        it "deletes rows that aren't the latest or latest tagged" do
+          subject
+          expect(db[:materialized_matrix].where(consumer_version_number: "2").count).to eq 0
+        end
+
+        it "deletes orphan pact_versions" do
+          subject
+          expect(db[:pact_versions].count).to eq 2
+        end
+
+        it "deletes orphan versions" do
+          subject
+          expect(db[:versions].where(number: "20").count).to be 1
+          expect(db[:versions].where(number: "30").count).to be 0
+          expect(db[:versions].where(number: "40").count).to be 0
+          expect(db[:versions].where(number: "50").count).to be 1
+        end
+      end
+    end
+  end
+end