My friend, work colleague and cousin by marriage, Ross Lazar, who has died aged 72 of cancer, was a psychotherapist and organisational consultant who spread British psychoanalytic ideas across Europe. A central part of his career lay in psychoanalytic psychotherapy and its associated observational studies. But in parallel he also developed a second strand working with groups and organisations.

Born to Jack, a businessman, and Pearl (nee Wachs), a legal secretary, in New Jersey, Ross came to Britain in the early 1970s to train at the Tavistock Clinic in London, where the Kleinian school of psychoanalysis – grounded in the observation of infants, children and families – had been established.

In 1978 he moved to Munich, where he played a pivotal role in spreading the Kleinian approach to continental Europe and especially Germany. He set up an adult and child psychotherapy practice in Munich and created the Bion Forum, bringing senior London-based psychoanalysts and psychotherapists to Germany for clinical and observation seminars.

Having attended and then been on the staff of the Leicester Conference, a long-established group relations training programme run by the Tavistock Institute, Lazar’s work with groups and organisations also began to flourish. He was a consultant to charities, small businesses, industrial companies and churches as well as two major German psychoanalytic training organisations, which he brought together in dialogue and collaboration. He also undertook group and organisational work in Austria, Israel, France, Norway, Hungary, Italy and Poland.

Ross is survived by his mother, his wife, Gisela, their children, Sebastian and Katrin, and two grandchildren, Fabian and Ferdinand.