The Solicitors Regulation Authority has sought assurances from law firms linked to the leaked Panama Papers that they are looking into the matter fully as it emerges that a former partner at one of those firms, Simmons & Simmons, is helping to lead the government investigation.

Simmons has been identified by the media as giving English law advice in relation to the formation by Panamanian law firm Mossack Fonseca of offshore fund Blairmore Holdings, while Holman Fenwick Willan has also been linked to the leak, which has seen Mossack Fonseca achieve the ignominious record of being the source of the largest data leak in history.

An SRA spokesperson told Legal IT Insider: “We are writing to those firms identified in the media as being linked to the Panama papers to ask for assurances that they have looked into the matter and have acted appropriately. We are also liaising with other authorities with an interest.” One of the authorities is understood to be the Financial Conduct Authority.

Simmons has declined to comment on the matter, in which it has emerged that Edward Troup, now executive chair of HMRC, one of the government department overseeing the inquiry into the Panama Papers, is a former Simmons partner. According to his LinkedIn page, Troup was a partner at Simmons between 1997 and 2004.

Neither Troup nor Simmons or any of its clients have been accused of any wrongdoing and a HMRC spokesperson told Legal IT Insider: “Before joining the Civil Service in 2004, Edward Troup had a successful career in the private sector, during the course of which he dealt with many companies. He can confirm that he never had any dealings with Mossack Fonseca, was unaware of the company until recently, and that none of the individuals or organisations named so far were clients that he advised.

“Edward Troup’s role in HMRC has never involved responsibility for operational activities or direct dealings with companies on their tax affairs. In any event, the governance in place at HMRC means that any Commissioners who have a potential conflict of interest would exclude themselves from any investigation or settlement involving a taxpayer with which they had had dealings in their previous careers.”

Holman Fenwick Willan, which has also not been accused of any wrongdoing, was not immediately available for comment.

The Mossack Fonseca leak, which came about via an anonymous tip off to German newspaper Süddeutsche Zeitung, has brought into sharpest relief the potential consequences of a law firm security breach, which the legal profession has been warned about with growing urgency over the past two years.

Tim Smith, a partner at insurance and risk law firm BLM, said: “The Law Society and other professional bodies have been warning firms of these types of threats and their potential consequences for a long time now. If professional advisers are to reduce the risks of a cyber attack, they need to ensure they have a clear understanding of the information they hold, where they hold it and ensure that the most sensitive information is the hardest to access. They also need to have strategies in place in case the worst should happen and it would be wise for them to have an insurance policy which covers them against this type of risk and which will provide the full range of support that they will need following this type of incident.”