Investigation Officer Abu Haider Md Shamsuzzaman of the case confirmed the matter late Thursday night.
Earlie in the day, a team of Gaibandha police arrested Rana from the capital based on the information divulged by three other suspected killers of Liton, who were detained from Gaibandha's Bridge Road area on Tuesday.
Later, he was brought back to Gaibandha and produced at a magistrate court in the afternoon, leading to the submission of his confessional statement under Section-144 of the Penal Code, Shamsuzzaman added.
In another development, police seized a firearm filled with six bullets and an empty magazine from the Sundarganj residence of former Jatiya Party MP Abdul Quader Khan, the so called mastermind of the killing, from the same constituency.
Gaibandha's Superintendent of Police Ashraful Islam revealed the information in a press briefing at his office on Thursday afternoon, saying they also seized Quader's passport and copies of tickets he gave the killers to flee after Liton's murder.
So far, police managed to seize two firearms, a shotgun cover, ten bullet shells, a mobile SIM card and a motorbike what they said were used in the killing mission, while they were looking for a third firearm linked to the incident.
Also Read- Another pistol used in Liton murder recovered from Quader’s house
Sundarganj police station's Officer-in-Charge Atiar Rahman said police with the help of firefighters raided Quader's village home in the upazila on Wednesday, but remained unsuccessful until Thursday early hours.
According to Atiar, the seizure of the second firearm followed an extensive search based on the information given by Quader, who was earlier put on a ten-day remand on Wednesday, a day after being detained from Bogra.
Police on Wednesday claimed they unearthed the motive behind the killing by tracing the source of a magazine containing six bullets left abandoned by snatchers at Nayabazar of Dhopadanga area on Gaibandha-Sundarganj road in the early hours of December 1.
After Liton was shot dead at his village home in Sundarganj upazila’s Masterpara on December 31 last year, police had asked Quader to surrender his licensed pistol and bullets.
But, he just deposited ten out of 40 bullets without a satisfactory explanation over the rest ammunition, greatly helping find the clue of the murder, police said.
Also Read- ‘Quader planned MP Liton murder’
Meanwhile, police are looking for Chandan Sarkar, office secretary of Sundarganj upazila unit of Awami League who went into hiding after Quader's detention, for his suspected connection in the murder.
Tracking his call list, police said Chandan was in good terms with Quader.
He had helped the killers with information about Liton, police said, adding, Chandan did it all out of his political vengence since Liton had expelled him for extortion and other criminal acts in the area.
Ever since the expulsion, Chandan, as police said, started expressing his disgruntlement on Liton. Even, he openly used to criticise Liton, causing a deep rivalry.