The bizarre case ended with the authorities arresting both the would-be hitman, as well as the woman and her daughter, police said in a statement.
The woman and her daughter went to a police station in central Madrid in mid-June to file two separate complaints, the statement said.
The first complaint was against the woman's romantic partner — who she claimed had tricked her out of more than €60,000 ($68,000) over the years.
The second was against her son-in-law who had agreed to kill him, police said.
Her son-in-law offered to kill the woman's romantic partner after being told by her daughter about the alleged scam.
He claimed to be a head of Spain's secret services and asked for an advance of €7,000 to carry out the killing, promising then to sell the man's organs and recover the €60,000 that the woman had been swindled of.
“The murder never happened and the women felt tricked,” the police said.
The man and the two women are accused of incitement to commit murder.
Police said the would-be victim was found in perfect health.