Tributes have been paid to Dr Marta Shahbazi, 41, a Cambridge scientist who died in the Spanish train collision on Wednesday that killed at least 69 people, according to the Guardian.

The source says Shahbazi was an affiliate associate professor at the Cambridge Stem Cell Institute and a group leader at the Medical Research Council Laboratory of Molecular Biology (LMB) in Cambridge. She was travelling on one of the trains involved in the crash near Urda in Toledo province.

The LMB said she had recently won the Spanish Society of Developmental Biology's scientific excellence prize. She was due to receive the award at the society's conference in El Rompido, Andalucía.

In a LinkedIn post, the LMB said it was "deeply saddened" by her death, calling it "a profound shock and a huge loss." It described her as "an inspiring, talented and passionate scientist" whose research shed light on the earliest steps in the development of human embryos and on errors that lead to failed pregnancies. The LMB said she had written about balancing her family and career, describing herself as a "mother scientist." She was a mother of two.

Dr Roser Vento-Tormo, a group leader at the Wellcome Sanger Institute, wrote that Shahbazi was "a close collaborator, a treasured friend, and an inspiration." She said the two had co-supervised two students and that some of their work will still be published in the coming months.

The Center for Research in Molecular Medicine and Chronic Diseases (CiMUS) in Santiago de Compostela, Spain, called her "a brilliant young researcher."

The disaster was Spain's second high-speed rail crash this year. Both occurred on the line between Madrid and Seville. Three days of national mourning began on Thursday. Prime Minister Pedro Sánchez described the incident as a "tragedy" and promised an investigation.