Catherine Dyer, who recently retired as crown agent at the Crown Office, said the centuries-old practice was “out of kilter” with legal systems across the world.
Ms Dyer said the Scottish Government’s failure to abolish the law was allowing sex offenders to escape justice. Those in favour of abolishing corroboration – the requirement for two independent pieces of evidence to bring a case to court – believe its removal would help increase conviction rates in rape cases.
However, the Scottish Government last year chose to drop the provision from the Criminal Justice (Scotland) Bill following a storm of protest from the legal fraternity.
Ms Dyer said the government would be forced to “revisit” corroboration because the current system was failing to protect the public.
She said: “There is not another jurisdiction in the world where [corroboration] is a requirement.
“When I speak at international conferences, I have to preface it with an explanation [of the Scottish system] and people are incredulous...it’s out of kilter with what the rest of the world thinks is justice.”
Justice secretary Michael Matheson last year called for more time to consider the future of corroboration following the publication of a report by Lord Bonomy which looked at legal safeguards.
Lord Bonomy’s report made a series of recommendations, including a requirement that police video all interviews with suspects and that the practice of dock identification – when the accused is identified as the perpetrator in court – be ended.
Mr Matheson said the proposals were “substantial and complex” and would have a considerable impact.
Thomas Ross, president of the Scottish Criminal Bar Association, said he continued to believe scrapping corroboration would be “very dangerous”.
He said: “It was a terrible idea in the first place, so nobody was surprised when it was kicked into the long grass.
“There was zero support for it outside of Lord Carloway and the administration.
He added: “I have never understood the argument that if you only need one source of evidence, then there will be more convictions. You will get more cases reaching court and more acquittals.”