Two holiday firm employees have been found not guilty by a Greek court over the deaths of a brother and sister who were poisoned by carbon monoxide.

Christianne Shepherd, seven, and her six-year-old brother Robert, from Wakefield, West Yorkshire, died after a faulty boiler leaked gas into their bungalow in Corfu in October 2006.

Three judges sitting at Corfu Town courthouse cleared Thomas Cook employees Richard Carson, 28, and Nicola Gibson, 26, of manslaughter by negligence. Of the 11 people who went on trial over the deaths, three were found guilty of manslaughter by negligence and one of breaching building regulations. The tour operator said that "the thoughts and sympathy of everyone at Thomas Cook will always be with the family and friends of Christianne and Robert Shepherd. We have always maintained that this tragic accident was the result of a unique set of circumstances, none of which could be the responsibility of the company or Richard Carson and Nicola Gibson."

Outside the courthouse, the children's father, Neil Shepherd, hit out at the verdict. "Nobody deliberately set out to cause Christi and Bobby's death, but everyone who worked on or knew about the disgusting state of the boiler in our eyes were grossly negligent. We paid money to Thomas Cook to send us to a hotel they considered safe. Our faith in this company was misplaced and abused."