AceShowbiz - One Direction alum Niall Horan was seen for the first time since the sudden death of his former bandmate, Liam Payne. On October 17, Horan was spotted out for a walk in London with his girlfriend, Amelia Woolley, and their dog.

Horan appeared distraught, sporting a green jacket, navy pants, and a Muirfield Village golf club cap. His eyes were hidden behind black sunglasses, and his expression was somber.

Payne, 31, died on October 16 after falling from a third-floor balcony at the CasaSur Palermo Hotel in Buenos Aires, Argentina. According to reports, he had checked into the hotel three days prior and was found dead in the hotel's internal courtyard. Authorities confirmed that Payne "jumped from the balcony of his room" before his death.

Horan, 31, issued a joint statement along with other One Direction members to express their devastation. Louis Tomlinson additionally issued a separate statement and so did Zayn Malik.

"I am beyond devastated to be writing this but yesterday I lost a brother," Tomlinson wrote. "Liam was somebody I looked up to everyday, such a positive, funny, and kind soul."

Harry Styles' mother, Anne Twist, also shared a broken heart emoji on social media after Payne's death, and Payne's family released a statement expressing their heartbreak and asking for privacy.

Police investigating Payne's death are reportedly searching for "key witnesses" who could be among the last people to see him alive. They interviewed five people including two unnamed women who was at the star's hotel room hours before his death. The singer died instantly after suffering multiple injuries that led to "internal and external hemorrhaging."

Horan and Payne had reportedly been planning a reunion before Payne's death. Payne had traveled to Argentina to attend Horan's concert on October 2 and was seen interacting with fans and dancing to the music.

The music industry insider revealed that Payne had struggled with finding his path as a solo artist and had been envious of his former bandmates' success.