"The Singapore Police Force (SPF) can obtain TraceTogether data for criminal investigations, said Minister of State for Home Affairs Desmond Tan in Parliament on Monday (Jan 4)"[1]

This was a reversal from earlier promises that it would only be used for contact tracing Covid19 exposures.

[1] https://www.channelnewsasia.com/singapore/singapore-police-f...

https://news.ycombinator.com/item?id=28070335 has links to instances in DE, SG, and AU.

German police have been using it to track down theft