I am just going through this (or will be very shortly) myself. I have an Australian CPL, have spoken to an ATO and read CAP 804 - relevant bit is:
3.3.1 Undertake Part-FCL CPL (H) theoretical knowledge instruction as determined by the Head of Training of an approved training provider and pass all Part-FCL theoretical knowledge examinations at CPL level. Applicants who wish to attempt the ATPL(H) (VFR) examinations must undertake an approved ATPL(H) Modular theoretical knowledge course as set out in Part-FCL Appendix 3(H) and pass all Part-FCL ATPL(H) (VFR) examinations. Applicants who wish to attempt the ATPL(H) with IR examinations must undertake an approved ATPL(H)/IR Modular theoretical knowledge course as set out in Part-FCL Appendix 3(H) and pass all Part-FCL ATPL(H) with IR examinations.
3.3.2 Complete at an Approved Training Organisation approved to conduct CPL modular courses the minimum flight time under instruction in a helicopter as outlined at 1.3.4 below.
3.3.3 Pass the Part-FCL CPL (H) skill test.
3.3.4 Minimum instruction depending upon total hours as pilot of helicopters:
Level 1: Experience > 1000 hrs: Min 7 hrs (23 hrs credit)
Level 2: Experience 500 – 999 hrs: Min 10 hrs (20 hrs credit)
Level 3: Experience 250 – 499 hrs: Min 15 hrs (15 hrs credit)
Level 4: Experience 185 – 249 hrs: Min 20 hrs (10 hrs credit)
Level 5: Experience 155 – 184 hrs: Min 25 hrs (5 hours credit)