Perth businessman Michael Mercanti, who founded the Mike's Multi Service chain, and his wife Sybil are suing Westpac for allegedly allowing their son Tyrone to withdraw more than $3.9 million from their bank account without consent.

Perth businessman Michael Mercanti, who founded the Mike's Multi Service chain, and his wife Sybil are suing Westpac for allegedly allowing their son Tyrone to withdraw more than $3.9 million from their bank account without consent.