  I propose a new axionic solution to the strong CP problem which involves a
hypothetical vector-like quark(s) in a high-colour representation of the
conventional QCD. There are two distinct scenarios. If the current mass of the
exotic quark is zero, the strong CP phase can be trivially rotated away. The
high-colour quark is `hidden' in various bounds states, the lightest being the
composite axion field, with properties similar to the standard invisible axion.
If the high-colour quark acquire a non-zero current mass due to the spontaneous
chiral symmetry breaking, the composite axion can be heavy, while the strong CP
phase is still cancelling out in the vacuum. The phenomenology and cosmological
implications of the heavy composite axion differs drastically from the standard
invisible axion.
