Part of a hospital's casualty department had to close for 12 hours when the body of a millionaire shipping magnate was found to be giving off toxic fumes, it emerged yesterday.

The "chemical incident" evacuation was ordered when Sir Derek Bibby's body arrived at Arrowe Park hospital on the Wirral on Wednesday afternoon. He had been terminally ill with leukaemia, and it is thought he took aluminium phosphide - a rat poison that gives off poisonous fumes when mixed with water.

The department reopened at 5.45am yesterday. Five staff at the hospital suffered minor breathing problems.

Sir Derek, 80, had been taken there after he was found collapsed at his home in Willaston, Cheshire. He was president of the Bibby Group (which contains the Bibby Line shipping firm as well as logistics operations and financial services), a 200-year-old family business based in Liverpool and with offices throughout the world.

Sir Derek had wanted to die peacefully and with the minimum of fuss, it was reported. He is thought not to have been aware of the consequences of taking the poison.

Because of the risk to patients and hospital workers from his contaminated body and clothes, the hospital's emergency chemical incident procedure was triggered and a large part of the A&E department was evacuated. Patients were taken to other hospitals in the region.

A spokesman for the family said: "Sir Derek Bibby had been ill with leukaemia for some time and was having blood transfusions five weeks ago. As his health and energy deteriorated he decided to end his life. He was a very proud and strong-willed individual who was not afraid of death.

"The family would like to offer its sincere thanks to the fire brigade, police and hospital staff."

Sir Derek was married with five children and nine grandchildren. He was a keen gardener and sportsman. He served in the Royal Artillery and in 1942 won a Military Cross for gallantry.