Popular fury has targeted officials in the eastern region that suffered 225 deaths and widespread destruction in the October 29 floods, Spain's deadliest such disaster in decades.

A criminal investigation into alleged homicide and injuries due to negligence led by a judge in the flood-hit town of Catarroja has also focused on them because regions are responsible for emergency management in the country's decentralised political system.

The judge ordered Valencia's ex-interior minister Salome Pradas and former emergencies official Emilio Argueso to testify on a date to be confirmed, the Spanish judiciary said in a statement.

A mass telephone alert to warn residents on October 29 was sent well after floodwater was already gushing through towns and claiming victims.

The alert "was late and mistaken" and the storm that triggered the floods "was not an unforeseen weather event" because national weather agency AEMET had already warned about it, the judge wrote in her ruling.

"The problem does not lie in the absence of information... rather in the fact that faced with this information, it was either ignored, its scope was not understood, or relevant decisions were not taken by those with decision-making power," she added.

In a statement after the announcement, Pradas said she would "always be willing" to help disclose the truth about the management of the floods.

"I continued, from the first minute to the last, to fulfil the institutional functions that were my responsibility according to the applicable rules" during those critical moments, she added.

The judge rejected lawsuits filed against other officials in the regional administration -- notably Mazon -- and a central government environmental body responsible for monitoring river levels.

Mazon has withstood months of intense scrutiny for his role in the catastrophe and calls for his resignation.

The judge also raised the number of victims in Valencia to 225 by including a woman who died in hospital after the floods interrupted her leukaemia treatment.

Three people are still reported missing.