A Spanish adventurer walking from Madrid to the World Cup in Qatar was reportedly arrested in Iran after visiting the grave of Mahsa Amini, the young woman whose death has triggered ongoing protests.

Santiago Sanchez began his pilgrimage by foot from Madrid, Spain in early January to see the football tournament. He traveled across Europe and Türkiye, sleeping in a tent, hotels and wellwishers' homes, before entering Iraq.

Throughout his journey, he posted on social media.

He told Reuters in Zakho in Iraqi Kurdistan last month that he hoped he might meet the Spanish team and inspire them to victory in the 2022 World Cup. "If you don't set a date for your dreams, you don't realize them," he said, explaining that the Nov. 20 kick-off date drove him on through extreme heat and uncertainty about his next meal or bed.

The 41-year-old was last heard from on Oct. 1 when he sent friends a picture of himself on the Iraq-Iran border with the caption: "Entry to Iran."

Some Spanish media suggest Sanchez had been arrested by the Iranian authorities, and his parents in Madrid told Telecinco TV channel that was the most likely possibility.

More than three weeks later, the Hengaw Organization for Human Rights reported that Sanchez was being held by Iranian intelligence in a detention center in Sanandaj.

The Spanish daily El Pais and Iran International, a Persian language broadcaster based in London, also confirmed the story.

Reports said Sanchez was arrested after visiting Amini’s grave in Saqez, near the northern Iraq border he crossed on his way to Qatar.

"A 99% chance that he is in a prison in Iran, but the (Spanish) embassy has told my daughter that until they go to the prison to see him and have the permission of the Iranian government, they cannot give that news," his mother Celia said.

Police summoned the parents to provide dental records, personal items such as a toothbrush and photos of Santiago's tattoos, which they will send to Interpol, she explained.

Sanchez is a former paratrooper who previously rode his bike from Spain to Saudi Arabia.

He appears to have been caught up in the protests that continue to rage 40 days since Amini was killed in police custody for allegedly not correctly wearing her hijab.

Iran’s Intelligence Ministry said in late September that it arrested nine foreign nationals from Germany, Poland, Italy, France, the Netherlands and Sweden in connection with the protests.