A three-member body headed by Additional Police Super Robiul Islam was formed to look into the allegation, said acting superintendent of police ASM Shamsur Rahman.
The committee is also asked to submit a report within three working days, he added.
On Thursday night, police arrested Sirajul Islam Jibon, district assistant correspondent of Channel S, early Friday from his residence at Gorurbazar in the district town on charges of carrying out attack law enforcers.
On Friday morning, police took the journalist to hospital citing that he was injured in mass beating. Later in the afternoon a district court sent him to jail after being produced before it for attacking policemen.
Meanwhile, several cultural organisations formed human chains in the town on Saturday demanding immediate release of Jibon and punishment of the policemen involved in the torture.