The half-metallic Heusler alloy Co2FeAl (CFA) is a promising candidate material for high-frequency spintronic devices. As many of these device structures involve bilayers of CFA and Pt, and rely on properties arising due to this interface for their functionality, understanding the proximity magnetisation that may be induced in Pt by proximity to CFA is very important. The polarisation usually found in Pt is too small to be observable by PNR. However, we find evidence from conventional magnetometry and resonant x-ray scattering for an unprecedented large polarisation in Pt layers beneath CFA thin films. We intend to use magnetic scattering length density profiles extracted from PNR to confirm and quantify uniform half-metallicity in CFA, magnetisation corresponding to an integer multiple of the Bohr magneton per formula unit, and the very large polarisation of Pt layers adjacent to it.