  We present preliminary results of a partial-wave analysis of
$\tau^-\to\pi^-\pi^-\pi^+\nu_\tau$ using data from the Belle experiment at the
KEKB $\mathrm{e}^+\mathrm{e}^-$ collider. We validate our model with a
model-independent analysis. We see the $\mathrm{a}_1(1420)$ and a
G-parity-violating $1^-[\omega(782)\pi]_\mathrm{P}$ wave in tauon decays. Our
results will improve models used in simulation studies necessary for measuring
the electric and magnetic dipole moments and Michel parameters of the $\tau$.
