The current precision of measurements at LHC experiments cannot exclude the possibility that a Standard Model like Higgs boson is a CP violating mixture of CP even and CP odd states. We
have addressed that possibility here, in a full simulation of the ILD experiment at 1 TeV center-of-mass energy ILC. Higgs interactions are probed in the HZZ vertex in vector boson fusion
production of Higgs bosons. It is found that the mixing angle between states of opposite CP parities can be measured with the absolute statistical uncertainty of 3.8 mrad, for the pure scalar,
corresponding to fCP =1.44 x 10-5 at 68% CL.