Colchester Hospital: Statements taken in inquiry
17 December 2013 Last updated at 12:38 GMT
Three separate inquiries are under way over claims staff were pressured into changing figures to meet government targets.
One former manager told BBC Look East he had volunteered to be interviewed by Essex Police "to help provide context and information to support their initial review".
All investigations into Colchester General Hospital are ongoing and no wrong-doing has been found or admitted.
The trust said it would take disciplinary action over anything improper.
Julian Sturdy reports: