I have no problem with this really, if it was littering, and not just smoking. There is never a reason to drop litter. Take it home, and if you don't like that, don't create any litter in the first place.
But ... was this on public land or pub land? If pub, then their rules should be clearly displayed but it would be nothing to do with the police (afaik), and if public, then not a private security matter? Although ...
According to Keep Britain Tidy:
"People who drop litter can be fined or face prosecution in court. Authorised officers have the power to issue a fixed penalty charge of up to £80 for a litter offence, as an alternative to prosecution. If the offender is prosecuted and convicted in court, the fine could rise to £2,500."
https://www.keepbritaintidy.org/faqs/advice/litter-and-law#:~:text=Dropping litter is illegal.,could rise to £2,500.
But, who are "Authorised officers"?