The Local Government have produced a guidance note drawing on examples of good practice in response to spiking allegations.  On its website, the LGA wrote:

From Autumn 2021 there has been an increase in reports of spiking, including a new trend of allegations of substances being administered by needles rather than through drinks. Councils take these allegations extremely seriously and with partners have responded swiftly to these reports. This short guidance note draws on examples of good practice in response to spiking allegations. It is not intended to provide a detailed guide to safeguarding in the night-time economy but aims to provide a brief overview of spiking, suggest some preventative actions licensed premises and licensing authorities can take, highlight some best practice case studies, and share a checklist that the LGA would encourage licensing authorities to consider.