| Amy Davies | Secretary | 23 Nov 2020 | 3 May 2022 | - | - |
| Caroline Ann Litchfield | Director | 25 Jun 2003 | 23 Jun 2009 | British | 57 years |
| Christopher Frederick Cliffe | Director | 5 Oct 1992 | 31 Mar 1993 | British | 76 years |
| Christopher Round | Director | 13 Jul 2006 | 6 Nov 2009 | British | 63 years |
| David Peacock | Director | 1 Oct 2019 | 1 Feb 2022 | British | 52 years |
| David Westbrook Anstice | Director | 21 May 1993 | 4 Oct 1994 | Australian | 77 years |
| Deepak Kumar Khanna | Director | 4 Nov 2009 | 30 Jun 2014 | American | 60 years |
| Francis Herman Spiegel | Director | 5 Oct 1992 | 29 Sept 1994 | American | 90 years |
| Gertraud Polz | Director | 6 Sept 2016 | 23 Jun 2017 | Austrian | 51 years |
| Graeme Bell | Director | 23 Jun 2009 | 5 Nov 2009 | British | 58 years |
| James Russell Jackson | Director | 1 Jan 2001 | 31 May 2003 | American | 80 years |
| Judy Carol Lewent | Director | 5 Oct 1992 | 14 Aug 2007 | American | 76 years |
| Katherine Elizabeth White | Director | 31 Dec 2014 | 18 Mar 2016 | British | 67 years |
| Keith Bousfield | Director | 23 Mar 2012 | 31 Dec 2014 | British | 66 years |
| Kevin Edward Mcardle | Secretary | 4 Apr 2007 | 30 Jun 2011 | British | - |
| Louise Jane Houson | Director | 6 Sept 2016 | 1 Oct 2019 | British | 49 years |
| Marc Charles Dalby | Secretary | 5 Oct 1992 | 19 Jan 2007 | British | - |
| Mark Andrew Charles Mcdowell | Director | 4 Nov 2009 | 31 Dec 2013 | British | 70 years |
| Melissa Leonard | Director | 11 Dec 2013 | 15 Oct 2016 | Usa | 53 years |
| Michael Craig Moran | Director | 6 Jul 2021 | 6 Oct 2023 | British | 51 years |
| Michael Thomas Nally | Director | 30 Jun 2014 | 30 Sept 2016 | American | 49 years |
| Richard Robinski | Secretary | 28 Jun 2011 | 23 Nov 2020 | - | - |
| Robert Armitage | Director | 19 Sept 2003 | 23 Mar 2012 | British | 70 years |
| Robert John Armitage | Director | 10 Dec 1993 | 1 Jan 2001 | British | 70 years |
| Simon Nicholson | Director | 31 Dec 2014 | 6 Jul 2021 | British | 50 years |
| Steven Robert Klimczak | Director | 1 Nov 1994 | 1 Oct 2000 | American | 72 years |
| Vincent Michael Lawton | Director | 5 Oct 1992 | 28 Jun 2006 | British | 76 years |