The 57-year-old man from Borgo Virgilio in northern Italy reportedly claimed his mother's pension every month for three years after her death in 2022.
According to the newspaper Corriere della Sera, he kept her body in the cellar of her home, without reporting her death.
His ruse was discovered by an astute city clerk after he disguised himself as his mother in an attempt to renew her ID card at the local council office.
Francesco Aporti, the mayor of Borgo Virgilio, told Corriere della Sera that the man dressed as "an old woman."
"He wore lipstick, nail polish, jewelry and old-fashioned earrings, and had a dark brown bob of hair," he said.
Video footage shows him walking to the council office with a cane.
The man eventually confessed to being the son and allowed officers to search his mother's home, where they discovered her body.
An autopsy has been ordered to determine how she died.
Corriere della Sera reported that the man was an unemployed nurse and was collecting over €50,000 in pension payments annually.
He is being investigated for concealment of a corpse, impersonation, and fraud against the state.