Legal groups and whistleblower advocates have commended Attorney-General Mark Dreyfus for ordering the prosecution of lawyer Bernard Collaery over national security leaks be dropped, ending a four-year saga sparked by Australia’s efforts to spy on the government of East Timor.

The former ACT attorney-general was set to face trial in Canberra later this year, after being charged in 2018 with offences under the National Security Information Act for allegedly seeking to help his client, the intelligence operative known as Witness K.