(Fotolia)

A doctor in Brazil has been arrested for allegedly using silicone fingers to trick the hospital's punch-in clock into thinking colleagues showed up for overtime shifts, local media reports.

The alleged fraud involved 11 doctors and 20 nurses at the Office of Mobile Emergency Care near Sao Paulo, police said, G1 newspaper reported. Police were tipped off from an anonymous source and investigators installed surveillance on the hospital. The hospital's punch-in system is a machine that scans fingerprints.

Thauane Nunes Ferreira, 29, was arrested Sunday on charges of falsifying a public document.

She alleged director Jorge Cury facilitated the fraud as a "condition of employment," the newspaper reported. Police seized six silicone fingers. Cury, however, denied the claims.

"The health secretary called me and now I am going to the police station. This is absurd. I've been a city official for 25 years and I've never known of this happening," G1 reported.