The decision to station a single permanent security guard outside the premises was made in August 2022 by Customer and Local Services after a number of incidents.
At the time, anti-social behaviour complaints had more than doubled from 18 in 2021 to 41 in 2022.
The added security comes out of the taxpayer-funded Library’s budget and a request made under the Freedom of Information Law showed it had cost £20,142.75 between December 2022 and December 2023.
A breakdown of the agency’s fees was unable to be provided by Government for reasons of commercial sensitivity.
Behaviour complaints have dropped again since the introduction of the guards, with incidents totalling 25 last year.