Dhaka, March 11 (IANS): Evidence related to the murder of Bangladesh-born blogger-writer Avijit Roy has been given to the US's Federal Bureau of Investigation (FBI), police said on Wednesday.

Dhaka Metropolitan Police spokesperson Monirul Islam said on Wednesday that Bangladeshi investigators handed over 12 or 13 pieces of evidence, including two machetes, a bag and blood samples to the US investigative agency, bdnews24.com reported.

Bio-engineer Roy, a US citizen, had been receiving threats from radicals for his secular blogging. Two of his books were published in this year's Ekushey Book Fair.

His assailants attacked him and his wife on February 26 on the Dhaka University (DU) campus while they were returning from the book fair.

Avijit died soon after being rushed to the Dhaka Medical College and Hospitals.

His wife and fellow blogger Rafida Ahmed Banna, also a US citizen, was seriously injured and went back to the US for better treatment.

Police recovered the two machetes and the bag just 50 yards away from the crime scene.

An FBI team has already inspected the spot of the crime near the Teachers and Students Centre (TSC), located in the heart of the university campus.

They have also spoken to the slain writer's father Ajay Roy, a former physics teacher at the university.

On Tuesday, Dhaka's chief metropolitan magistrate allowed the evidential items to be examined at the FBI's laboratory after investigators filed a plea.

A man, Shafiur Rahman Farabi, was arrested from Dhaka four days after the incident .

Farabi, known for preaching radicalism, had reportedly threatened, on Facebook, to kill Avijit.