Rifat Farazi, son of Dulal Farazi of Dhansiri area of the municipality, is the number two accused in the sensational murder case.
Md Sirajul Islam Gazi, senior judicial magistrate of Barguna, passed the order when Md Humayun Kabir, Inspector of Sadar Police Station and the investigation officer (IO) of the case, sought a 10-day remand for interrogating him.
In the early hours of Wednesday, a police team arrested Rifat Farazi from the municipality area.
The main accused, Sabbir Ahmed alias Nayon Bond, was killed in a reported gunfight with police in Sadar upazila on Tuesday.
He was buried at the family graveyard of his maternal grandfather at Burjirhat village in Sadar upazila on Tuesday night.
Rifat Sharif, 22, was hacked to death by criminals in front of his wife Ayesha SiddikaMinni in broad daylight in the district town on June 26. The incident was caught on surveillance camera.
Ten people, including five FIR-named accused, have so far been arrested over the murder.
On Monday, two accused -- Mohammad Oli and Tanvir Hossain -- reportedly confessed before a court here to their involvement in the killing.