These are the requirements for the making of a production order.
There must be reasonable grounds for believing that—
the offence specified in the application has been committed by the person so specified;
the person is in the United Kingdom or is on his way to the United Kingdom;
the offence is an extradition offence within the meaning given by section 64 (if section 157(3) applies) or section 137 (if section 157(4) applies);
there is material which consists of or includes special procedure material or excluded material on premises specified in the application;
the material would be likely to be admissible evidence at a trial in the relevant part of the United Kingdom for the offence specified in the application (on the assumption that conduct constituting that offence would constitute an offence in that part of the United Kingdom).
The relevant part of the United Kingdom is the part of the United Kingdom where the judge exercises jurisdiction.
It must appear that other methods of obtaining the material—
have been tried without success, or
have not been tried because they were bound to fail.
It must be in the public interest that the material should be produced or that access to it should be given.