The incident occurred when the officers wanted to close a bar which defied the presidential guidelines.
The officer was detained yesterday but has not yet been charged.
The victim, Gift Phiri, is battling for his life at St Francis Mission Hospital in Katete and hospital sources have disclosed that his condition has worsened.
Last week, Eastern Province police commissioner Luckson Sakala told journalists that the victim was hit by a stray bullet on July 24 around 21:00 hours and was still in hospital.
“We received a report of a shooting incident which took place in Petauke during the general security patrols that the police officers were conducting in Petauke. The officers came across a bar which was open and there were a lot of people that were drinking beer at the same bar. They were trying to enforce the Presidential directive of Covid-19 that no bar should actually be opened,” he said.
Mr Sakala said the victim met his fate when the drunkards became unruly and threw stones at the police officers.
“In the process the police officers fired some gunshots trying to scare those people but unfortunately one of the stray bullets hit one of the people who were drinking beer. He was rushed to St Francis Mission hospital where he is actually receiving treatment,” he said.
He appealed to members of the public to cooperate with the police as they enforce the Presidential directive that no bar should be open during the Covid-19 period.
Mr Sakala said there was a directive that no bar should be opened, adding that people should adhere to it.
“All of us are aware that the Covid-19 pandemic is real, we need to join hands to complement the efforts of the government which stipulates that we follow the health guidelines that have been put in place,” Mr Sakala said.