Liam Payne‘s father is sharing his grief with his son’s fans in Argentina … standing with them in an incredibly poignant moment right outside the hotel where Liam died.

The heartbreaking scene played out Friday evening in Buenos Aires … Geoff Payne solemnly walked around the makeshift memorial fans have created on the sidewalk in front of the CasaSur Palermo hotel.

As Liam’s dad looked at all the flowers, letters and candles … fans observed a moment of silence in honor of the singer.

It’s been an emotional day for Mr. Payne — earlier in the day he went to meet law enforcement officials at the Buenos Aires Judicial Office.

TMZ broke the story … police are focusing on the drug paraphernalia that was in Liam’s room — telling us they found a narcotic called “Cristal,” which causes extreme highs, lows and aggressive behavior.

That description does align with what a hotel manager said on the 911 call made moments before Liam’s death.

Although an autopsy has been completed, toxicology results are still pending, so we don’t know if Liam was using the substance.