An invention is new if it does not form part of the state of the art on the date the relevant patent application is filed or priority acknowledged. The state of the art consists of everything made available to the public by means of a written or oral description, by use, or in any other way, anywhere in the world.
The Industrial Property Division does not have the power to determine whether an invention is new, and so you will need to carry out what is known as a prior art search. You can do this by checking patent databases such as Patentscope or Espacenet. The service is free of charge.
When filing a patent application with the Industrial Property Division, you can, however, ask for a preliminary search report (carried out by the European Patent Office).