Human rights defender and pro-democracy campaigner Nguyen Anh Tuan has been detained and interrogated about his writing on property giant VinGroup on his Facebook page. Mr. Tuan, a permanent resident of the central city of Danang, said he was detained by security officers upon arriving at the Tan Son Nhat International Airport in Ho Chi Minh City in the early morning of May 25. During the next 15 hours in police custody, he was interrogated consecutively by many security officers who were introduced as officers from the Department of Anti-reactionary, Terrorist Affairs (A67) under the Ministry of Public Security. They repeatedly asked him where he was going and with whom he would meet, with the apparent objective of making him tired, Tuan said. Finally, a man who introduced himself as Vu came to meet with Tuan. It is likely Vu is the head of the A67's Representative Office in the southern region. Affirming that he would do anything in his powers to protect the communist regime, Vu threatened that if Tuan does not stop his activities, he will receive heavy consequences. At the end of the meeting, Vu requested Tuan delete his writing because it affects the national security. Specifically, Vu asked the activist to remove his recent articles about VinGroup, a listed property giant with billionaire Pham Nhat Vuong being its chairman. In these posts, Tuan explained how Vinh Group cooperates with state officials to grab public land at cheap prices, and Tuan used many facts from state media in his writing. Tuan questioned the legality of Vu's request, but the security officer remained silent, saying unless Tuan removes his posts, security forces will use strong measures against him. Before releasing Tuan, security officers confiscated his personal documents, including his passport and identification card. They explained that by this move, they can force him to go to another meeting with security officers in Hanoi. Mr. Tuan is among well-known rights campaigners in Vietnam. He has participated in many events to advocate for human rights improvement, including Vietnam's Universal Periodic Review in 2014. Due to his activities, security forces once confiscated his passport when he returned from an advocacy trip abroad. However, recently, under international pressure, Vietnam's Ministry of Public Security was forced to grant him with the new passport and allow him to go abroad.