An entire trust non-executive board has been swept aside, following failures in 'human relationships' between members brought together after a four-way merger last year.

The five non-executive directors of Community Health South London trust and chair Suhail Aziz have resigned, just a year after they were appointed.

Community Health South London trust merged the 'community' elements of Lambeth Healthcare trust with Optimum Health Services trust in April 1999.

Mental health services went to South London and Maudsley trust, itself formed in a merger between Bethlem and Maudsley trust and Lewisham and Guy's Mental Health trust.

Mr Aziz was formerly Lambeth Healthcare trust's chair. Valerie Vaughan-Dick was a non-executive from the same trust. Ruth Ashton, Jeremy Fraser and Sally Hawkins were from Optimum. The sixth member to resign, Alan Ruben, was new to the NHS.

Difficulties between the non-executive directors led London regional office to order an external review. It would only say this week that 'the problem was about human relationships not working, and that can happen in any organisation'. It also said the six had been 'prepared to stand aside to enable. . . a fresh start to be made'.

Health secretary Alan Milburn has appointed Ansel Wong as trust chair and Anne-Marie Nelson and Evelyn Dunwoody as non-executive directors.

Mr Wong has been chair of Brent and Harrow health authority since 1998.

Ms Nelson was chair of the High Security Psychiatric Commissioning Board until she resigned over the Fallon inquiry into the personality disorder unit at Ashworth Special Hospital. Ms Dunwoody became a non-executive director at South London and Maudsley trust last month.