When Brazilian police raided the house of Wallace Souza, a popular Amazonian MP who doubles as a TV presenter, they might have expected to find scripts for the next episode of his daily crime show.

Instead they discovered more than $150,000 (£90,000) in cash, a stash of weapons and a tatty piece of paper with the names of at least four dead men whose executions, police claim, Souza might have ordered in an attempt to boost the ratings of his lunchtime TV show.

Police in Manaus were this week re-opening dozens of unsolved murder cases after a 12-month investigation which authorities said indicated that the politician was the head of a sprawling criminal organisation involved in drug trafficking, gun-running and death squad killings which got air-time on his daily crime programme Canal Livre – a move designed to bolster viewing figures.

"Former employees have told the police that state deputy Wallace Souza ordered that certain facts were created for the programme," said Thomas Vasconcellos Dias, the police intelligence chief behind the investigation.

Fifty-year-old Wallace Souza has denied the charges, describing the allegations as a "plot" against him. Isabella Siqueira, his spokesperson, blamed the accusations on a conspiracy by criminals whom he had denounced. "He has made it very clear that he has nothing to do with these things and he will carrying on working as normal. He maintains that he is innocent."

Calls to Souza's lawyer went unanswered today .

Dias said there were "strong indications" that Souza was the brains behind a criminal network with links to drugs in a city where authorities say traffickers earn nearly $25m a month.

Most of Souza's alleged victims were local criminals or rivals, Dias said. "Some were partners while others were adversaries," he said, adding that he believed Souza's son, Raphael, had been personally responsible for some of the killings and had tipped off his father's news team so they could arrive at the crime scene first.

A report by the public prosecutor, seen by the Guardian, says: "The programme of his father, deputy Wallace, always arrived [at the scenes] first."

Investigations into Souza's activities outside the newsroom began in October, following the arrest of Moacir Jorge da Costa, a former police officer who, Dias claims, told police that at least one of the murders had gone to air on his employer's TV show. Police then began investigating the MP's son, Raphael, who is in jail on drug trafficking and homicide charges.

In his statement to police, Costa claimed Wallace Souza had ordered his employees to "barbarise" the city of Manaus so as to create news.

Costa's arrest triggered the raid on Souza's house during which police recovered the piece of paper, in the bedroom belonging to Souza's son, which bore the names of the dead men.

A report compiled by Manaus' public prosecutor gives details of several men who might have been killed on the orders of the Amazonian politician. Among them was Alessandro Silva Coelho, 28, who was shot 20 times last July while sitting in his brand-new Mercedes Benz.

The report also mentions other possible victims, among them Coelho's father, Luiz Alberto Coelho, who was murdered in February this year, and Cleomir Pereira Bernadino, 50, who was described by the local press as one of Manaus' biggest drug traffickers and was executed with 17 shots in January 2007.

Dias said the execution of a man known as Luiz "The Flea", which featured on Canal Livre, was also being investigated. Dias claimed this person was a hitman who had been hired by Souza to execute a federal judge and was killed after turning the job down.

Among the unsolved crime cases now being re-examed is the murder of 19-year-old Diego Rocha, killed by masked men who invaded his Manaus home in April.

Souza, who was facing an ethics committee in Manaus today, at present enjoys immunity from prosecution because of his politician position but he could be arrested if he were removed from power, Dias said.