The man, who cannot be identified before his June court appearance, faces 45 counts of stealing, allegedly committed between September 2005 and October 2008.

The charges, laid yesterday morning, marked the conclusion of a complex, long- term investigation by Tasmania Police's Launceston criminal investigation branch.

Detectives allege that the accountant's deception began within weeks of him being granted power of attorney over his client's considerable funds upon the elderly man entering a nursing facility.

"He then used his client's own cheque book to misappropriate those funds on 45 separate occasions," Detective Senior Constable Darren Turner alleged yesterday.

The cheques were written in amounts varying between $1000 and $20,000 and were deposited into various accounts, allegedly either belonging to or accessible by the accountant.

The alleged large-scale deception escaped detection until the client's death in February last year.

"The executors of the will notified his sole beneficiary of the details of the estate - at which point it became apparent that a significant amount of money was missing," Detective Senior Constable Turner said.

"Police were notified at that point and the investigation began."