Erin Patterson has been found guilty of murdering three relatives by serving them a beef Wellington laced with poisonous mushrooms, in a case that shocked Australia.

A jury on Monday found an Australian woman guilty of murdering three people, including her parents-in-law, by poisoning them with a dish laced with death cap mushrooms, an act that sparked a years-long legal saga and gripped the nation.

Erin Patterson's conviction for the deaths by poisoning of her estranged husband's relatives has prompted fevered speculation across Australia about her motive.