  Analytic expressions for the angular distributions of the $b$-quarks
associated with single $t$-quark production in $p \bar p \to W^* \to t \bar b
\to b \bar b W$ and of the leptons from the subsequent decay $W \to l\nu$ are
obtained in the laboratory system. CP violation in the $t$-production vertex is
assumed. Different angular and total cross section CP violating asymmetries are
considered. Relations testing CP violation solely in the $t$-decay vertex are
also obtained. A numerical analysis is performed in the MSSM with a CP
violating phase of the trilinear coupling $A_{\tilde t}$. The asymmetries are
typically of the order $10^{-3}$ - $10^{-4}$.
