Police today detained another suspect in the killing of 13-year-old boy in Jalalabad area in Sylhet city.

Ruhul Amin, 29, was allegedly involvement in attempts to conceal the body after the death of the boy, said Akhtar Hossain, officer-in-charge of Jalalabad Police Station.

He said Ruhul is a brother-in-law of Rajon murder accused Ali Haider, reports our Moulvibazar correspondent.

Immediately before the arrest of Ruhul, police said all of the accused in the sensational Rajon murder case have been detained by locals from different parts of Sylhet.

With this development, nine people including the four accused have been detained in connection with the murder of Rajon, the 13-year-old boy who was tortured to death by a group of brutes who were "punishing" him in Kumargaon Bus Stand area of Sylhet on July 8.

Meanwhile, no Eid festivity could touch the victim's family today, as the family is still grieving for the departed soul, reports our Moulvibazar correspondent after visiting the victim's family this afternoon.

"The Eid brought us nothing but the bittersweet memories of my son. We will observe Eid on the day Rajon's killers will be tried," Rajon's mother Rubina told The Daily Star.

"He [Rajon] loved me so much. He used to bring gifts for me with the money he could save by selling vegetables," Rajon's younger brother Sajan burst into tears.

"My son is never going to come back. How can we celebrate Eid without my son?" Rajon's father Azizur Rahman could not resist his emotion.

Rajon's "crime", the accused claimed, was theft. In the video footage that went viral on July 12, Kamrul, another accused, was seen beating Md Samiul Alam Rajon mercilessly.

He, his brother Muhit Alam and some others beat the minor boy to death. One of them filmed the brutal beating and shared it on social media, sparking outrage at home and abroad.

The 28-minute video clip created a furor on the social media as it went viral. Since then, different organizations have been demonstrating across Bangladesh, demanding the maximum punishment for the culprits for their heinous crime.

Jalalabad Police Station accused Muhit Alam, his brother Kamrul Islam, Moyna Mia and Ali Haider of the murder case.

A Sylhet court has granted police seven days to grill Ali Haider over the murder of Samiul Alam Rajan. Sylhet Metropolitan Magistrate Anwarul Haque granted the remand on Friday.

Investigator Detective Branch Inspector Suranjit Tarafder said he appealed for 10 days. The court also gave police seven days to quiz accused Muhit Alam and Ismail Hossain Ablus. Their five-day remand ended on Friday. Locals have nabbed Ali Haider, the last of the four accused in Sylhet Sadar Upazila, and handed him over to the police.

Jalalabad police OC Akhter Hossain told The Daily Star he was picked up from Shekhparha with help of locals around 11:15am on Friday.

The 34-year-old is the brother of Muhit Alam and Kamrul Islam, who were picked up before. Moyna Mia, the security guard accused of abetting the three brothers in the killing, had been picked up on July 14.

A day before Mia's arrest, Kamrul Islam had been taken into police custody in Jeddah by the local police after the Bangladesh embassy in the Saudi Arabian city sought their help.

Locals caught Muhit Alam on July 8 when he was trying to dump Rajan's body. He was later handed over to police.

Police in the past two days also detained Alam's wife, brother-in-law, and two others who witnessed the gory torture on the boy for questioning. Alam and another suspect are currently in police remand. The others arrested for killing Samiul are Lipi Begum, wife of the accused Muhit, brother Ismail Hosain ablush (33), Feroz Ali and Azmat Ullah.

A Sylhet court has ordered police to transfer Rajon's case to the Detective Branch (DB) of police.

The court of Sylhet Metropolitan Magistrate-1 Sahedul Karim passed the order on Wednesday. Rahmant Ullah, an ADC of the Sylhet Metropolitan Police, confirmed the matter to The Daily Star. He said: "The case will soon be handed over to DB police once all the formalities are done." The video was not recorded in secret, said Akhtar Hossain, officer-in-charge of Jalalabad police station. "The criminals themselves recorded the heinous incident and uploaded it to the internet; they enjoyed doing it," he told.