Following her resignation, Lister did freelance work for BBC News and for South Africa's Capital Radio 604. In December 1984, Lister exposed a document authorising the interception of her mail by South African authorities, causing her to be arrested and detained for a week under the Official Secrets Act.
Following her departure, Lister engaged in temporary assignments with BBC News and South Africa's Capital Radio 604. In December 1984, Lister uncovered evidence showing that South African authorities had been monitoring her correspondence, prompting her arrest and detention for a week under the Official Secrets Act.