West Yorkshire ambulance service's former chief executive is among four people due in court to face charges of conspiracy to defraud the NHS.
Trevor Molton, 49, of Pickering, North Yorks, and his wife Angela, 42, are due before Dewsbury magistrates on Friday.
John Miners, 53, the former finance director at West Yorkshire Metropolitan Ambulance Service (WYMAS) is also due to appear in court with them.
The fourth defendant is businessman Paul Buckley, 34, of Horsforth, Leeds.
Damning report
The charges follow a long-running investigation by the NHS Counter Fraud Service and West Yorkshire Police into allegations of irregularities at WYMAS in 2000 and 2001.
An NHS Counter Fraud Service spokesman said: "The NHS Counter Fraud Service can confirm that four individuals have been summonsed to appear at Dewsbury Magistrates' Court on Friday.
"While the investigation is ongoing it would be inappropriate to comment further."
Mr Molton was dismissed as WYMAS chief executive in April 2004 for misconduct unrelated to the investigation.
Mr Miners resigned in 2003 after a damning report into the running of a nursing agency by WYMAS.