A Brazilian politician who fronts a popular television crime show is being investigated for allegedly ordering a series of executions in a bid to boost his ratings.

Wallace Souza, a former police officer who used his lunchtime television slot to rail against the violence sweeping the jungle city of Manaus, is suspected of commissioning at least five murders to prove his claim that the region is awash with violent crime.

"Manaus can no longer live with this wave of crime," Souza, 50, frequently told the audience of his daily show Canal Livre. "Nowadays everyone is killing."

In a 2008 speech at Manaus's local parliament, Souza boasted that Canal Livre enjoyed complete editorial freedom and was conducted with "journalistic responsibility".

But prosecutors in the remote Amazon city say the politician's actions went far beyond the call of journalistic duty, accusing Souza of links to drug trafficking, death squads and organised crime, and possessing illegal arms.

"Our investigations indicate that they went as far as creating facts," Thomaz Augusto Correa, the local police intelligence chief, told a Brazilian news channel. "Crimes were committed in order to create news for the group and for the programme."

Souza was the most voted-for politician in the last elections in the state of Amazonas and is in his third term. But his transformation from politician and TV presenter to suspect began last October when his former security guard Moacir Jorge da Costa, an ex-police officer, was arrested and accused of nine murders. Costa reportedly confessed that at least one of the murders had gone to air on his employer's TV show.

The arrest triggered a police raid on Souza's house that uncovered more than £100,000 as well as an arsenal that included several high-calibre assault rifles. So far nearly 20 people have been arrested in connection with the case, including Souza's son and several senior police officers.

Francisco Balieiro, Souza's lawyer, said that his client denied the charges, blaming them on a political campaign against him. Souza's private secretary, Isabella Siqueira, told the Guardian yesterday that Souza was being targeted because of his involvement with investigations into the smuggling of drugs and weapons into prisons in Manaus.