Migrant boat disaster: Spain challenges Nato over distress call claim Migrants are helped off a boat arriving from Libya on the Italian island of Lampedusa. Photograph: Filippo Monteforte/AFP/Getty Images The Spanish government has challenged a claim by Nato that the alliance forwarded a distress call that could have saved the lives of 63 African migrants adrift in the Mediterranean to a nearby Spanish warship. It said that if there was such a message, Nato should be able to "prove it." Pressure is mounting on Nato to respond to a series of unanswered questions concerning the tragedy of the migrant boat, with European politicians repeating their demands for a further inquiry, and human rights lawyers announcing the launch of legal action against those responsible for the "avoidable" loss of life. On Wednesday the Guardian revealed the findings of a damning official report into the fateful voyage, which saw 72 sub-Saharan refugees drifting in the sea for two weeks and all but nine of them dying of thirst and starvation. This was despite them being located by European authorities and distress calls being broadcast from Rome to all other ships in the area. The report by the Council of Europe blamed a collective set of "human, institutional and legal" failures for the inaction and labelled it a "dark day for Europe." It concluded the large loss of life could have been avoided if the various agencies in the area - Nato, its warships, the Italian coastguard and individual European states - had fulfilled their basic obligations. Despite initially insisting that Nato "had not logged any distress signals from the boat and had no records of the incident," this week the organisation admitted it had received a fax giving details of the troubled boat and its precise location. A spokesman claimed the information "was forwarded to Nato taskforce units under its operational control," which would have included the Méndez Núñez, a Spanish frigate equipped with helicopters that was positioned only a few miles from the migrants at the time. On Thursday the Spanish Ministry of Defence denied that any such communication was received. "The frigate did not receive any notification from the Maritime Rescue Co-ordination Centre of Rome or from the Nato command in Naples," spokesman Miguel Morer told the Guardian. He said that had they been aware of the migrant boat's plight, Spanish forces would have moved quickly to effect a rescue. If [any notification] was sent then there must be a record ... so if Nato says there was a message, then it should be able to prove it. Nato said it did not have any further information on the matter. The gravity of the dispute was underlined when lawyers from the International Federation of Human Rights said they would launch criminal lawsuits against those they believe may have been responsible for ignoring the migrants' pleas. "There is no doubt that someone, somewhere, has criminal responsibility for the deaths of these people," said Stéphane Maugendre, president of the Paris-based Groupe d'Information et de Soutien des Immigrés [Group for information and support of immigrants]. He said legal action would initially be launched in France as the French military had "the largest presence" in the Mediterranean at the time, but said co-ordination was already under way for similar lawsuits in other European countries. Confusion continues to surround the fate of another set of emergency messages broadcast by the Italian coastguard appealing for nearby vessels to help save the migrants. Sent over the Inmarsat and Hydrolant communication systems, which all vessels, including military ships, are supposed to be equipped to receive, the messages were labelled "Priority: Distress," the highest emergency phrase possible under the international search and rescue convention. But the Spanish authorities claim no such calls were received. "We deny absolutely having received these messages on the frigate," a spokesman said.