Six people have been charged with manslaughter over the deaths of two children in Corfu, Greek officials say.
A date has been set for the children's funeral
Robert Shepherd, six, and his sister Christianne, seven, of West Yorkshire, died from carbon monoxide poisoning during a holiday with their father.
Tour firm Thomas Cook says none of its employees are among the six, but says it "will form part of the enquiry".
The six are also charged with causing bodily harm through negligence and face up to five years in jail if convicted.
Earlier, Corfu authorities had said a Thomas Cook employee was amongst those charged, but the firm denies this.
Officials said the hotel director, general manager and maintenance manager, as well as the air conditioning installation manager and a maintenance employee, had been charged.
BBC correspondent Malcolm Brabant, in Corfu, said Greek police had not released the names of those charged because of legal restrictions.
The family, from Horbury, near Wakefield, were staying in a four-star bungalow at the Louis Corcyra Beach Hotel last week when the carbon monoxide gas seeped into the property.
The children's father Neil Shepherd, 38, and his girlfriend, Ruth Beatson, 27, survived the poisoning and are now being treated at Pinderfields General Hospital in Wakefield.
The Greek tourism ministry has already withdrawn the hotel's licence and indicated this move would be permanent if the deaths were established to be the responsibility of the management.
In a statement, UK-based Thomas Cook said: "We do understand that we will form part of the enquiry.
"Thomas Cook has always said that it wants to co-operate fully in any investigation, and we are concerned that there has been no contact with us by the police or any other authorities, despite our efforts to speak to them." The company said it was undertaking an internal investigation and that the hotel had been audited according to UK guidelines.
A British coroner earlier opened and adjourned two inquests into the deaths of the children.
West Yorkshire Coroner David Hinchliff promised to "fully, fairly and fearlessly" investigate the deaths of the children.
The children's funeral will be held in Wakefield on Tuesday.