  We present a new measurement of the unitarity triangle angle phi3 using a
Dalitz plot analysis of the KsPi+Pi- decay of the neutral D meson produced in
B->D(*)K decays. The method exploits the interference between D0 and D0bar to
extract the angle phi3, strong phase delta and the ratio r of suppressed and
allowed amplitudes. We apply this method to a 605 fb-1 data sample collected by
the Belle experiment. The analysis uses three decays: B->DK, and B->D*K with
D*->DPi0 and D*->Dgamma, as well as the corresponding charge-conjugate modes.
From a combined maximum likelihood fit to the three modes, we obtain phi3 =
78.4^+10.8_-11.6 +- 3.6 (syst) +- 8.9 (model) degrees. CP conservation in this
process is ruled out at the confidence level (1-CL)=5x10^-4, or 3.5 standard
deviations.
