Dhaka: The two witnesses to the terror attack in a Dhaka cafe on July 1 have been missing even though police have claimed that they were released on the night of July 6. The families of Tahmid Hasib Khan and Hasnat R. Karim said that neither had returned home, the Dhaka Tribune reported. On July 2 the security forces rescued at least 30 hostages ending 12-hour siege. Tahmid and Hasnat were then taken in as witnesses along with other survivors of the terror attack on Holey Artisan Bakery and O'Kitchen Restaurant in Dhaka's diplomatic enclave. All the survivors of the Gulshan cafe attack, except Tahmid and Hasnat, were released the day after their rescue. According to sources in the police department, both of them gave separate statements about the incident. It was not made clear why they were detained for another 72-hours, the Dhaka Tribune said. And it is not clear where the two survivors - Tahmid, a student of the University of Toronto, and Hasnat, a former teacher of the North South University ended up after their release. Family members of Tahmid, a Canadian resident, have been running campaign on social media to get him back. They also tried to get him released citing his medical condition as he is an epileptic, but failed. "They have been released after interrogation," Deputy Commissioner of Dhaka Metropolitan Police Masudur Rahman said on Sunday night. He, however, did not specify the exact time of their release. Monirul Islam, Additional Commissioner of Counter-Terrorism and Transnational Crime Unit of police, on July 6 afternoon said that police had not detained or arrested Tahmid. "They are just being questioned as they witnessed the incident," he said. The two police officials’ versions suggest that Tahmid and Hasnat were released on the night of July 6, hours before Eid. However, both the families confirmed that they had not returned home as of 11 p.m on Sunday, nine days after the July 1 carnage that claimed at least 22 lives. Police earlier said they were looking into their alleged involvement in the Gulshan attack as circulated on the social media. Tahmid's father, Shahriar Khan said: “If the state needs to question him, they should, but they should let us know where he is.” Hasnat’s father, Rezaul Karim, also confirmed that his son was still missing, the Dhaka Tribune said.