A medical billing clerk was the mastermind behind 20 fake brain surgeries, creating paperwork that allowed three people to steal $300,000 from the GHI insurance firm, federal prosecutors said Friday.

Nine brain surgeries were claimed for just one family -- for the husband, wife and two sons -- and all the claimed procedures never happened, said the United States Attorney for the Southern District of New York and the U.S. Postal Inspection Service.

An additional nine brain surgeries -- all fictitious -- were also claimed for a second family, said U.S. Attorney Michael Garcia.

By doctoring medical records for about three years, clerk Charles Pritchett, 39, of Mount Vernon, replaced the names of real patients with the names of the three suspects and their relatives, creating fraudulent insurance claims reimbursed by GHI, said Garcia.

Suspect Stanley Canella, 36, of Manhattan, is accused of getting $142,268 in fake claims for nine brain surgeries never performed on himself, his wife and their two sons, Garcia said.

Nine was the number again for bogus brain surgeries that netted defendant Dorothy L. Smith, 42, of Manhattan, $131,397, Garcia said. Smith herself also received three separate reimbursements for the same fake procedure, according to the charges.

Suspect Michael Biscotti, 37, of Staten Island, falsely claimed that he and his wife had brain surgery, giving him $31,041 in insurance reimbursements, according to the charges.

Canella is at large, but the other three suspects were arrested and charged with various fraud counts. Upon conviction on all charges, Pritchett could face up to 90 years in prison while the others face maximum terms of up to 30 years.