Helen Close is a Research Associate at the Omega Research Foundation, an NGO that researches the manufacture, trade in, and use of conventional arms and law enforcement equipment. She has worked at Omega since 2009 and works on number of issues including researching the manufacture of specific weapons of concern, the manufacturing capabilities of various countries, weapons identification and export controls. Recent areas of research have included the manufacture of incendiary weapons, the manufacturing capabilities of the United Arab Emirates and the trade in and use of less lethal weapons and other law enforcement equipment used to commit acts of torture and other ill-treatment.

Close also sits on the board of Drone Wars UK and is a trustee of the small grant making body the Trust for Research and Education on the Arms Trade. From 2008-2019 she sat on the Steering Committee of Campaign Against Arms Trade.