Developer Dennis Oberhoff he has discovered traces of a new iMac with an Apple processor in the crash logs for Daftcloud, a Mac program that he developed.
The as yet unreleased Apple Silicon-powered iMac appeared in Xcode's Crash Reporter - this is a clear indication that Oberhoff's app was being used by an iMac with Apple Silicon processor.
9to5Mac has taken a closer look at the logs and made the assessment that the crash logs do indeed relate to a new iMac model powered by Apple Silicon.
Earlier in March various configurations of the 21.5in iMac disappeared from the Apple Store, leading to assumptions that a new model will launch soon. Currently the two entry-level models have a delivery date of 27 March to 3 April.