Law firm Appleby has given more details about last year’s cyber attack on its offices.

Its statement comes after Labour leader Jeremy Corbyn made allegations of VAT abuse involving the Isle of Man during Prime Minister’s Questions - and as the island braces itself for the first of a two-part Panorama exposé tomorrow.

Appleby said it believed illegally held documents stolen during the cyber attack on servers in a number of its offices was being used by international journalists for stories about the offshore world.

It described the journalists’ allegations as ’groundless’ and said the hack ’should be condemned for the criminal act it is’.

Appleby’s statement reads: ’Following the Leader of the Opposition’s comments in Prime Minister’s Questions, about a leak from an off-shore law firm, we wish to make it clear that our firm was not the subject of a leak but of an illegal computer hack.

’Journalists claim to have seen documents from multiple sources, including Appleby. During the cyber-attack, we believe, but we do not know for certain, that a limited number of private documents were stolen by criminals from servers in a number of our offices.

’Whilst we have taken robust measures to protect ourselves from further attacks, we believe that these illegally held documents will be used by journalists who will be publishing stories about the off-shore world in the next few days.

’We will continue to defend ourselves and our legitimate and lawful business against these groundless allegations.

’We are a global organisation comprising 10 offices which have equal prominence within the global business. We do not have a headquarters. ’It is not factually correct to state that Appleby has its headquarters in Bermuda or that this is a Bermuda cyber-attack.

’Cyber-crime is an enormous problem for individuals and businesses around the world and we believe that neither politicians nor journalists should condone or encourage it in any way for example by referring to material stolen in this way, unless that is absolutely necessary to discuss matters of great public concern.

’In this instance, that is simply not the case and we believe that the hack should be condemned for the criminal act it is and the privacy of the information respected.’Mr Corbyn told the Commons last week that '957 business jets in the Isle of Man seems a bit excessive for any island, anywhere'.He said: 'I hope it is investigated and due tax is collected from those people who are trying to avoid it.'The Isle of Man VAT avoidance allegations are part of a wider leak from the Bermuda-based law firm said to be of a similar scale to the Panama Papers. Will the Prime Minister commit the HMRC to fully investigate all evidence of UK tax avoidance and evasion from this leak and prosecute where feasible?’The Manx government has not issued a response to Mr Corbyn's claims.