Four people died after consuming a brew believed to have been laced with poisonous chemicals at Karuku village in Embu County.
Two of the victims died in their sleep on Wednesday after consuming the brew while the rest passed away the following day as they were being treated in hospital.
Those who perished have been identified by the police as Simon Kariuki, 56, Bernard Kirigi, 66, John Kamau, 42 and Stephen Mugo, 50.
Mbeere South police boss Gregory Mutiso said a trader supplying the killer brew had been arrested and his bar closed.
He also said the alcoholic drink had been confiscated and would be used as exhibit when the suspect appears in court.
Mr Mutiso told of how the trader hid the brew in a bush near Tana river after learning that it had killed some of his customers to cover up the evidence.
"Following a tip-off, we found bottles of the lethal brew stashed in a gunny bag and dumped in a bush close to the river," said Mr Mutiso.
Briefing the press at Makutano police station on Saturday evening, Mr Mutiso said the trader knew the brew was toxic and continued serving it to his customers.
He said the trader committed a ‘very serious’ crime and must face the law.
"We are consulting to know the proper charges which should be preferred against the suspect," he said.
Mr Mutiso said the bar belonging to the trader has been closed and will not be reopened.
"The trader will not be allowed to operate in this area and that is why the government has cancelled his liquor trading licence," he added.
Mr Mutiso said samples of the brew will be taken to the government chemist for analysis to establish the chemicals it contained.
"The brew is dangerous and its sale will not be allowed in this area," he said, advising the residents to avoid taking the liquor.
He warned that any other trader found in possession of the brew being sold in bottles will be dealt with ruthlessly.
"We don't want more people to die and therefore we are going round the area to check whether other beer dealers are selling the brew in their bars," said Mr Mutiso as he sent a message of condolences to the bereaved families.
According to the villagers, the victims who were friends went to the bar for merry-making after they receiving Sh35,000 cash from their welfare group.
They took as much beer as possible to get a strong kick as they chatted.
"After taking the beer, the victims started vomiting and complaining of stomach pains and left to their respective homes. Sadly two died at night," one of the villagers said.
Villagers said they learnt of the death of their colleagues with shock.
"We are still reeling in shock following what transpired," one of the villagers, Caroline Mbithe said.
A survivor, Raphael Mwendwa, 56 said he was lucky to be alive.
“I was drinking together with my friends but I sensed danger because the alcoholic drink was so strong. I felt it was not the normal liquor that I usually drink and therefore I took little of it and went home, leaving my friends in the bar. Later, I was shocked when I heard that all my friends were gone after taking the stuff. I think I survived because I didn't take much of it," said Mr Mwendwa.
Mr Mwendwa vowed that he will not drink any alcoholic drink again following what happened to his friends.
"Never again will I take alcohol," he said.