Plans for a drug injection facility in Dublin city centre have been delayed again after planners have raised queries over its operation and possible over-concentration of such services in the area.

Merchants Quay Ireland (MQI) have been told to come up with a detailed management and policing plan for the proposed injection centre.

Dublin City Council has also told the drug treatment group they have to show that there is not already an over-concentration of similar services in the area.

MQI have applied for planning permission to run the country's first supervised drug injection centre.

It wants to operate six booths with the primary aims being the reduction of disease transmission and drug overdoses as well as to connect addicts with treatment services.

However, the plan has provoked 101 objections from local residents, a nearby national school as well as business groups who say the area has already deteriorated because of the existing needle exchange facility at Merchants Quay.

They believe that the situation will get worse with an injection facility.

In its submission the Licensed Vintners Association said there are already 14 other drug treatment facilities within 2km of Merchants Quay and a submission on behalf of Temple Bar publican Martin Keane said there are 10 homeless service centres within 800 metres.

An objection was also received from Health Business Services, the business division of the Health Service Executive, which granted an operating tender for the injection facility to Merchants Quay Ireland. 

Many objectors claimed the centre would lead to an increase in drug dealing and crime, and expressed concern at the effect on nearby tourist facilities such as Christchurch Cathedral, St Patrick's Cathedral, Dublinia and Dublin Castle.

In its decision to request further information, council planners said MQI should provide information including a detailed policing plan, comparisons with established facilities in other countries, information on the number of clients expected and duration of visits and measures to prevent overspill of queues into the public realm.