Suspected members of a Dublin organised crime gang were remained in custody on Saturday after an assortment of drugs, guns, ammunition and a monkey were found on a halting site on Friday.

The raid also uncovered serious public health risks, with raw sewage running into the River Tolka.

Animal welfare officers with the DSPCA were on Friday night caring for the small marmoset monkey found in a cage on the site in Finglas. It is a breed native to the forests of South America.

An investigation is underway into where the monkey, valued at about €2,000, was sourced and how it was brought into the Republic.

Three guns were found during the operation including a machine pistol, a sub-machine gun and a .357 calibre revolver. Photograph: Garda Press Office handout

Three guns were found during the operation; a machine pistol, a .357 Magnum revolver and a machine gun with silencer.

Some 300 rounds of assorted 9mm and .357 ammunition was also found as well as 227 rounds of 12 gauge shotgun cartridges.

Cocaine and herbal cannabis, valued at approximately €100,000 and €30,000 respectively, was seized as well as a compressor for pressing drugs into small blocks.

A weighing scales was being used to package the drugs in parcels of specific weight and value. Ammonia was also seized and it was being used to make crack cocaine on the site.

Stolen clothing with the tags still attached and valued at about €3,000 was discovered and gardaí suspect it was taken during shoplifting sprees.

While the discovery of the monkey was very unusual, gardaí said the guns find was of most significance.

The monkey which was found by gardaí durign the raid in Finglas. It has been taken into the care of the DSPCA.

Supt William Carolan of Blanchardstown Garda station said the team of gardaí working in the force’s K district were “in the faces” of crime gangs.

“We have significant issues in our district at the moment, so the removal of these high velocity weapons; I have no doubt has saved lives,” he said in relation to feuding in the areas of Finglas, Blanchardstown and their environs.

“This is an organised crime gang and the level of firearms they have access to is quite frightening,” he added of Friday’s operation.

“The ability to deploy those firearms in any kind of feud situation is extremely concerning. These types of firearms are not readily available so to be able to remove them (is significant).

“These gangs will have to go and try and access those guns again and we will keep hitting them at every opportunity to keep removing firearms off the streets.”

Ammunition found during the search in Finglas. Photograph: Garda Press Office

He added the seized guns would be sent for forensic analysis and that would determine if any of the guns had been used in crimes, including murders.

While Supt Carolan did not comment on the origins of the guns, some firearms of the same kind have been supplied to Irish criminals by the Kinahan cartel.

As well as the monkey gardaí also found a variety of other animals including dogs and fowl; all on a site with a number of families.

After the team of about 50 gardaí, from Blanchardstown and Finglas stations backed by the Armed Response Unit, raided the site other responders were called in.

These included personnel from the DSPCA, investigators from the Department of Social Protection and Dublin City Council workers who deal with environmental pollution concerns.

Material seized by gardaí during the raid in Finglas.

Two men were being question under Section 30 of the Offences Against the State Act on Friday night in relation to the firearms and gardaí believe they are members of the gang being targeted. They can be held for up to 72 hours under the Act.

A woman was also being question on suspicion of handling stolen property in the shape of the stolen clothing.