  The behaviour of correlators at large distances plays an important role in
the dynamics of quantum field theories. In many instances, correlators satisfy
the so-called \textit{cluster decomposition property} (CDP), which means that
they tend to zero for space-like asymptotic distances. However, under certain
conditions it is possible for correlators to violate this property. In the
context of quantum chromodynamics (QCD), a violation of the CDP for correlators
of clusters involving coloured fields implies that the strength of the
correlations between the coloured degrees of freedom in these clusters
increases at large distances, which is a sufficient condition for confinement.
In this paper we establish a criterion for when the CDP is violated. By
applying this criterion to QCD, it turns out that certain lattice results
involving the quark and gluon propagators can be interpreted as evidence that
quarks and gluons are confined due to a violation of the CDP.
