Washing m/c fault trips circuit breaker. Need relevant engineer

We have had our ZANUSSI ZWF 14070 W1 washing machine for about 3 years and it has given us excellent service. About 3 months ago we had our fuse box replaced with a set of circuit breakers, by a qualified electrician. Until recently we have experienced no problems, but now the circuit breaker serving the washing machine trips out during the cycle. We called on the same electrician to check the circuits associated with the washing machine and he reported them as OK. (He replaced the machine’s sealed plug with one he wired in case the cause lay there, but the problem persists.) He is sure the problem is with the machine. The electrician advised us to find a tradesman qualified in dealing with washing machines to isolate and cure the fault.