City white-collar partners have played down concerns over conflicts issues presented by Slaughter and May's potential hire of former Serious Fraud Office (SFO) director David Green QC.

Legal Week revealed this week that Green is in talks with the magic circle firm, and that he is understood to have made an application to the Advisory Committee on Business Appointments, which reviews new roles being taken up by former ministers, senior civil servants and other Crown servants, in part to ensure there are no problems caused by conflicts of interest.

The director of public prosecutions, Alison Saunders, has also submitted an application to the committee ahead of her forthcoming move to Linklaters at the end of the year.

Green's tenure at the SFO encompassed a number of investigations into Slaughters' clients, including Rolls-Royce and Olympus, while the magic circle firm is also advising Ultra Electronics and British American Tobacco (BAT) on ongoing probes, raising concerns over the implications of Green potentially joining the firm.

Katten Muchin Rosenman white-collar partner Polly Sprenger, who was head of strategic intelligence at the SFO between 2008 and 2010, said that Green joining Slaughters would be a "logical step", adding that while conflicts may arise, Slaughters is likely to be able to manage them better than some other firms.

Sprenger said: "Because of how big the cases the SFO has tackled while Green was director are, a large number of firms will have acted on them in some capacity, so conflicts are inevitable. Having said that, because Slaughters does not take a very prominent role in some of the high-profile SFO criminal cases and instead does more civil work, they might be better isolated than other firms against a conflict.

"I think you would be hard pressed to create an effective Chinese wall for Green at a firm that has led the defence of a corporate entity in a high-profile SFO criminal investigation."

Multiple white-collar partners pointed to other firms such as Clifford Chance, which led on the SFO's criminal investigation into oil services company Unaoil, and Simmons & Simmons, which advised former Afren chief exec Osman Shahenshah on money laundering and fraud charges, as firms that would find it harder to effectively ringfence a hire such as Green.

It is a shrewd move by Slaughters that will make US firms look at them as a competitor in this area

One head of business crime at a City law firm, who acts for clients under SFO investigation, however, said that ongoing investigations opened by the SFO under Green's directorship could cause an issue, such as its bribery and corruption investigation into BAT.

They said: "Anything that the SFO is currently investigating would have to be looked at with care, and also matters that have been looked at by the SFO but not investigated could come back up in the future. But there are practical steps that will be taken to keep a person with knowledge that is contrary to a client's interest away.

"If a conflict issue arises, David would have to have nothing to do with the case itself and would have to be locked out of the files on the computer system. He would also have to be seated in an area or on a floor that would prevent cross-contamination."

Another former SFO lawyer, now a white-collar partner in private practice, said that while potential clients may be concerned about Green's links to the SFO, they were confident that Slaughters would be able to assuage such fears given that "ringfencing and Chinese walls are not a new thing".

Another City white-collar partner who has represented clients under investigation by the SFO echoed this, saying: "It is a shrewd move by Slaughters that will make US firms look at them as a competitor in this area. The SFO will make sure there are procedures put in place, but Slaughters are not making a short-term move here. They are looking at a long term plan; not to get insider information."

News of Green's talks with Slaughters have come as surprise to some, with many tipping him to make a lucrative move to a US law firm in London, with Gibson Dunn & Crutcher and Quinn Emanuel Urquhart & Sullivan previously cited as firms likely to be interested in taking him on.

Following his departure, the SFO appointed chief operating officer Mark Thompson as interim director ahead of the arrival of Green's full-time successor.

Former FBI deputy general counsel Lisa Osofsky, now head of investigations at regulatory compliance company Exiger, is thought by many in the market to be in line to take over as director, although the Attorney General's Office is yet to make an official announcement.