Australian woman Erin Patterson's lawyers argue that errors during the trial led to an unfair conviction, while prosecutors say her 33-year minimum prison term is too lenient.

Patterson was found guilty last year of murdering her husband's parents and elderly aunt, deliberately lacing their beef Wellington meal with highly toxic death cap mushrooms.

Australian mushroom killer Erin Patterson has failed to overturn a slew of convictions, and a judge instead imposed a heavier prison sentence for three "cold and calculated" poisoning murders.

Patterson was found guilty last year of murdering her husband's parents and elderly aunt, deliberately lacing their beef Wellington meal with highly toxic death cap mushrooms.

Patterson was found guilty last year of murdering her husband's parents and elderly aunt, deliberately lacing their beef Wellington meal with highly toxic death cap mushrooms.

An Australian appeals court has ordered triple-murderer Erin Patterson to never be released from prison because of the “shocking criminality” involved in poisoning four of her estranged husband’s relatives with death cap mushrooms.