The textReportDriver.deleteFile() function deletes the driver file that contains your report information.
textReport.textReportDriver.deleteFile()
In the following example, the report engine deletes the driver file that it created from a scratch file:
myReportDriver = TextReportDriver.createDriverFromTempFile();
myReport.setReportDriver(myReportDriver);
...
myReport.myReportDriver.deleteFile();