In all his years in Brazilian law enforcement, police chief Marconi Almino de Lima had never faced a case like this: a sordid tale of love, jealousy, a contract killer and kitchen condiments.

It all began in June when Maria Nilza Simões, a housewife in the small town of Pindobaçu, around 240 miles from Salvador, in the north-eastern state of Bahia, allegedly sought out a local gun for hire to do away with her husband's lover.

Carlos Roberto de Jesus, an unemployed ex-con, accepted the mission. For around £350 he agreed to kill Erenildes Aguiar Araújo, known simply as Lupita. According to one version, Lupita had been having an affair with Simões' partner and Simões wanted her rival out of the way. The day of the murder was to be 24 June.

All was going to plan until the novice hitman located his target. The hit turned out to be a childhood friend. Unable to go through with it, De Jesus grappled for a way out, eventually devising what he apparently thought was an ingenious solution: tomato ketchup.

Armed with two bottles of the sauce, he opened up to his friend, led her into the forest and staged a mock-execution with a mouth gag and a machete. Lupita was doused in tomato ketchup and a photo was taken as proof of death.

"I tore my own top, I stuck the knife in my side," she told a local newspaper. "He tied me up and threw the ketchup. He took a photo and delivered it to her."

The photograph – this week splashed over the front pages of Brazil's tabloids – shows Lupita's head tilted backwards, her body smothered with distinctly unrealistic-looking "blood" and a long knife, jammed comically under her arm-pit.

More Monty Python than CSI Miami, the photo nevertheless worked. Simões is said to have been taken-in by the image, shown to her on a mobile phone. The fee was paid.

But another twist was to come. Days later, Simões was walking in the local market when she saw her contract killer canoodling with the supposedly dead Lupita.

Furious, she marched into the local police station and reported him for theft. Her decision triggered the strangest investigation police chief Almino de Lima is ever likely to face.

"In eight years service I have never heard of anything like it and we hear a lot of stories," the police chief told the local Correio da Bahia newspaper.

All three characters are now facing charges. Simões for issuing death threats against Lupita; Lupita and De Jesus for extortion.

De Jesus, the ketchup killer, has reportedly skipped town while Simões faces public humiliation.

"Did she really not notice that the knife was stuck in the arm-pit?" Vera Márcia de Araújo, a local shopkeeper, told a local newspaper. "The whole town is laughing in her face."

Lupita, now a local celebrity nicknamed the "ketchup woman", seems to have come off best.

Reports on Friday suggested her newfound fame had led to her name being touted for a seat in the local town hall.

"That's what people are saying around here, but it's something I'll have to think about," she said.

Hélio Palmeira, the town's mayor, has claimed she has a good chance of being elected while Walterley Kuhin, a local radio-show host, also backed a future campaign: "The people around here are pretty fed up with the town hall. Why not get some ketchup in there?"