Arnold & Porter has become the third US firm this year to hire a senior lawyer from the Serious Fraud Office (SFO), bringing in fraud group head Kathleen Harris.

Harris, who will join the US firm as a partner in June, will become a part of Arnold & Porter's City white collar criminal defence team. In her role at the SFO, Harris oversaw all fraud cases, and monitored changes in the body's critical policy function.

Arnold & Porter London managing partner Tim Frazer commented: "The strategy behind the hire is to grow our economic crime unit here in London so that it mirrors our strengths in the US. With the arrival of Harris, we will be able to service existing clients with compliance and investigation issues, as well as building on our UK client base."

Commenting on the recent SFO hires made by US firms, Frazer said: "The Bribery Act is very ambiguous and broad in its approach – the fact that several US firms are hiring senior lawyers with significant expertise in this area is no coincidence."

The news comes a month after it emerged that two senior officials at the SFO had left the government body to join US firms Covington & Burling and White & Case.

The head of the SFO's anti-corruption team, Robert Amaee, left to join Covington, while Charlie Monteith – the body's head of policy – quit for White & Case's London base.