MIAMI (AP) _ A dozen people, including five doctors, were charged Thursday with cheating Medicare out of $15 million by creating fictitious patients and billing for services.

The former administrator of the Coral Gables-based Mederi home health care agency, 59-year-old Susan Regueiro, was in custody and others were being sought.

``The indictments are the latest examples of the success we are having in investigating health care fraud,'' Attorney General Janet Reno said.

``We have seen unprecedented increases in investigations, prosecutions and recoveries of money fraudulently billed by unscrupulous providers,'' she said.

The indictment comes at a time the federal government is struggling to police the burgeoning home health care business.

``These groups were using fraudulent patients, fraudulent visits, billing for services never rendered on patients that did not exist,'' said FBI spokeswoman Anne Figueiras in Miami. ``We believe more indictments are forthcoming on home health care agencies.

Regueiro and co-defendant Leopoldo ``Polo'' Perez created a large network of fictitious cases and kept a secret partial ownership, prosecutors said. The company made Medicare claims it knew to be fictitious and funneled the money back to the defendants, the government claimed.

Wilfredo Fernandez, a spokesman for the U.S. attorney, said this was the most lucrative home health care scam yet to result in a federal indictment.

``It was a very secretive trail and it took a lot of uncovering,'' Figueiras said. ``But our agents worked hard with the Internal Revenue Service to track them.''

The defendants were charged by a grand jury with 102 counts of conspiracy, fraud and money laundering. The money-laundering charges carry a maximum penalty of 20 years in prison with a fine of twice the amount of money laundered. The conspiracy, false claims and wire fraud counts are punishable by up to five years in prison and a $250,000 fine.

The physicians indicted were Nora Costa, 40, of Miami, Pedro Rene Benitez, 51, of Key Biscayne, Edward Cuni, 57, of Miami, Jesus Oliva, 40, of Miami, and Augustin Granda, 72, of Miami. Two certified home health-care aides _ Nilda Miranda, 67, of Coral Gables and Julia Concepcion Garcia, 39, of Miami _ were also charged.

The defendants allegedly submitted phony Medicare claims through a portion of Medicare, called Part A, that covers the burgeoning home health care business.