London (CNN) -- Police in England said Friday they have seized what could be the parts for Britain's first firearm made using 3-D printing -- but later said more testing is needed to establish if this is the case.
An initial news release from Greater Manchester Police said officers had found "a 3D printer and what is suspected to be a 3D plastic magazine and trigger which could be fitted together to make a viable 3D gun" when they searched locations Thursday in the Baguley area, near Manchester in northwest England.
But after doubts were raised, the force released a second statement stressing that the parts were still being examined.
"We need to be absolutely clear that at this stage, we cannot categorically say we have recovered the component parts for a 3D gun," Assistant Chief Constable Steve Heywood said.
"What we have seized are items that need further forensic testing by national ballistics experts to establish whether they can be used in the construction of a genuine, viable firearm.
"We will also be conducting a thorough analysis of computers we have recovered to establish any evidence of a blueprint on how to construct such a weapon."
U.S.-based tech blog Gigaom reported that it appeared the items police suspected of being gun components were in fact spare parts for the 3D printer.
The raid that netted the items was part of a planned week of action against criminal gangs in Manchester, police said. A man has been arrested on suspicion of making gunpowder and is being questioned.
In his statement, Heywood said the seizure had prompted discussion around the potential threats posed by 3-D printing.
"Clearly the fact we have seized a 3D printer and have intelligence about the possible production of a weapon using this technology is of concern. It (is) prudent we establish exactly what these parts can be used for and whether they pose any threat," he said.
"What this has also done is open up a wider debate about the emerging threat these next generation of weapons might pose."
Others have also raised concerns about the potential for 3-D printing to be used to create weapons.
This year, the U.S. State Department ordered Defense Distributed, a nonprofit group set up by a Texas law student, to remove instructions for printing a handgun with a 3-D printer from its website.
The group's founder, Cody Wilson, had posted a video online showing a single shot being fired from "The Liberator," a plastic handgun that, with the exception of a metal firing pin and a piece of metal included to comply with the Undetectable Firearms Act, was assembled entirely from parts made with a 3-D printer.
Wilson complied with the order, but not before the design had been downloaded more than 100,000 times.
The Victoria and Albert Museum in London subsequently acquired two models of the Liberator pistol, which were put on display last month as part of a design exhibition.
The Science Museum in London also has a Liberator on display.
CNN's Lindsay Isaac and Arion McNicoll contributed to this report.