Five former and current employees of Columbia/HCA Healthcare Corp. and Olsten Corp. got an early Christmas present: The U.S. attorney’s office in Miami notified them on Dec. 23 that it would not prosecute them on allegations relating to illegal kickbacks, according to several sources close to the investigation.

The decision culminates more than two years of investigation into questions surrounding Columbia/HCA’s 1997 purchase of Olsten’s home health care agencies. Olsten, which is based in Melville, N.Y., and has home health agencies throughout Florida, was the target of a Miami federal grand jury inquiry involving its relationship with Nashville-based Columbia, which itself has been the target of the largest health care fraud investigation in history.