Barcelona terror: Missing boy confirmed dead, toll rises to 14

A seven-year-old Australian-British boy missing following a terror attack in Barcelona has been confirmed dead.

Julian Cadman was with his family for a wedding when the van ploughed into a crowd at Las Ramblas.

"Julian Cadman's family has told us he is unfortunately one of the victims of the attack and has asked us to thank all the people who have spread the news," the missing persons bureau said in a statement.

"In these very unjust, hard and painful moments, we accompany Julian's family and friends. Rest in peace."

News reports at the weekend he had been found alive were quickly quashed by Spanish police.

His mother is believed to be in hospital in a serious condition.

"Julian was a much loved and adored member of our family," Julian's family said in a statement.

"As he was enjoying the sights of Barcelona with his mother, Julian was sadly taken from us. He was so energetic, funny and cheeky, always bringing a smile to our faces. We are so blessed to have had him in our lives and will remember his smiles and hold his memory dear to our hearts. 

"We would like to thank all those who helped us in searching for Julian. Your kindness was incredible during a difficult time."

Julian's death brings the Islamic State-claimed attack's toll to 14, with more than 100 injured.