A detective was paid more than £20,000 in overtime in a year, a BBC Freedom of Information request found.
The officer was working for West Mercia Police, which spent £9.5m on staff overtime costs over two years.
Elsewhere in the West Midlands region, Staffordshire police spent £8.57m, Cheshire £6.49m, West Midlands £3.29m and Warwickshire £352,407.