A former Bermuda premier predicted yesterday that under-siege law firm Appleby may not survive after confidential company information was hacked in a massive cyberattack.

Michael Dunkley, who led the country as One Bermuda Alliance premier until July’s election victory by the Progressive Labour Party, added that the firm’s reaction to the leak had been ham-fisted.

Mr Dunkley, in a post on Facebook, said: “This is a very serious matter and we must pay attention ... this is an Appleby matter and, sadly, because of how badly they handled the hack, I suggest that they will not be a viable entity going forward.”

Mr Dunkley, now a backbench Opposition MP, was speaking after the massive cache of documents hijacked from the Bermudian-founded law firm were made public at the weekend.

The documents, dubbed the Paradise Papers, were unveiled after a year’s work by the International Consortium of Investigative Journalists, who worked with nearly 100 media organisations around the world.

Mr Dunkley’s post said: “This is also a reputational issue for Bermuda and we must do all we can to answer questions on the matter, explain how we do business and make any changes required to strengthen the openness and transparency, but at the same time protect privacy as appropriate.”

The Paradise Papers are made up of more than 13 million documents from offshore law firms and company registries in offshore jurisdictions

About half of the documents — 6.8 million — came from a cyberattack on Appleby files.

The Appleby files, hacked last year, were obtained by the German newspaper Süddeutsche Zeitung and shared with the ICIJ.

Reports yesterday linked Appleby to a controversial Indonesian pulp and paper company, one of the world’s largest, which is said to have used a web of offshore companies to shuffle billions of dollars. The firm — Asia Pacific Resources International Holdings Ltd, known as April — is one of a dozen Asian-based forest product firms that have used Appleby in its business dealings.

The ICIJ said that documents obtained from the hack on Appleby and corporate services provider Estera, spun off from Appleby last year, showed how Appleby and major banks like Credit Suisse and ABN Amro had helped April structure its operations despite controversy over its environmental record.

The ICIJ report said: “Internal records from Appleby underline concerns of scholars, advocacy groups and government officials that the offshore financial system contributes to the expansion of companies involved in levelling forests and other practices that contribute to global climate change.

“Compounding the problem is the fact that Indonesia, home to the world’s third-largest expanse of tropical forests, has the highest rate of deforestation.”

The ICIJ said that the April group, which also produces palm oil and other products, began to take shape in 1994 with the formation of two companies in Bermuda, who retained Appleby for administration and legal services.