diff --git a/account_cancel_invoice_check_voucher/__init__.py b/account_cancel_invoice_check_voucher/__init__.py
new file mode 100644
index 000000000..7be6ed351
--- /dev/null
+++ b/account_cancel_invoice_check_voucher/__init__.py
@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+##############################################################################
+#
+#    Author Vincent Renaville. Copyright 2012 Camptocamp SA
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+
+from . import account_invoice
+# vim:expandtab:smartindent:tabstop=4:softtabstop=4:shiftwidth=4:
+
diff --git a/account_cancel_invoice_check_voucher/__openerp__.py b/account_cancel_invoice_check_voucher/__openerp__.py
new file mode 100644
index 000000000..75329fbaf
--- /dev/null
+++ b/account_cancel_invoice_check_voucher/__openerp__.py
@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+##############################################################################
+#
+#    Author Vincent Renaville. Copyright 2012 Camptocamp SA
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+{
+    "name" : "Cancel invoice, check on bank statement",
+    "version" : "1.0",
+    "depends" : ["base",
+                 "account",
+                 "account_voucher",
+                 "account_cancel",
+                 ],
+    "author" : "Camptocamp",
+    "description": """Constraint forbidding to cancel an invoice already imported in bank statement with a voucher.
+    """,
+    'website': 'http://www.camptocamp.com',
+    'date' : [],
+    'installable': True,
+    'active': False,
+}
+# vim:expandtab:smartindent:tabstop=4:softtabstop=4:shiftwidth=4:
diff --git a/account_cancel_invoice_check_voucher/account_invoice.py b/account_cancel_invoice_check_voucher/account_invoice.py
new file mode 100644
index 000000000..91112c334
--- /dev/null
+++ b/account_cancel_invoice_check_voucher/account_invoice.py
@@ -0,0 +1,55 @@
+# -*- coding: utf-8 -*-
+##############################################################################
+#
+# Copyright (c) 2012 Camptocamp (http://www.camptocamp.com)
+# All Right Reserved
+#
+# Author : Vincent Renaville (Camptocamp)
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+
+from openerp.tools.translate import _
+from openerp.osv import osv, orm
+
+class account_invoice(orm.TransientModel):
+    _inherit = "account.invoice"
+
+    def action_cancel(self, cr, uid, ids, context=None):
+        invoices = self.read(cr, uid, ids, ['move_id', 'payment_ids'])
+        for invoice in invoices:
+            if invoice['move_id']:
+                ## This invoice have a move line, we search move_line concerned by this move
+                cr.execute("""SELECT abs.name AS statement_name,
+                                     abs.date AS statement_date,
+                                     absl.name
+                              FROM account_bank_statement_line AS absl
+                              INNER JOIN account_bank_statement AS abs
+                              ON absl.statement_id = abs.id
+                             WHERE EXISTS (SELECT 1
+                           FROM account_voucher_line JOIN account_move_line ON
+                            (account_voucher_line.move_line_id = account_move_line.id)
+                            WHERE voucher_id=absl.voucher_id 
+                            AND account_move_line.move_id = %s )""",
+                               (invoice['move_id'][0],))
+                statement_lines = cr.dictfetchone()
+                if statement_lines:
+                    raise osv.except_osv(_('Error!'),
+                                         _('Invoice already imported in bank statment (%s) at %s on line %s'
+                                            % (statement_lines['statement_name'],
+                                               statement_lines['statement_date'],
+                                               statement_lines['name'],)))
+
+        return super(account_invoice,self).action_cancel(cr, uid, ids, context=context)