The 27-year-old from Madrid was with a group of friends on their way back from skating when they witnessed the attack in which at least seven people were killed and more than four dozen injured.

An eye-witness told his family how, rather than run for safety Echeverría, who works for HSBC in London, rushed to help a woman he saw being stabbed.

“He jumped off his bike and hit the assailant with a skateboard,”  his brother, Joaquin, wrote on Facebook. He was last seen “lying on the ground after defending the woman with his skateboard. He was brave, getting involved to save the woman.”

His family have taken to social media to appeal for information, after failing to trace him at the hospitals where the injured are being treated.”