Anonymous hackers have blamed spies within the collective for the arrest of 25 suspected members in Europe and South America.
In a statement released on its blog, Anonymous Iberoamerica, the Spanish-language branch of the movement, said the 25 were arrested not through "intelligence work or informatics strategy" but rather through "the use of spies and informants within the movement".
The activists said many of those detained had been sloppy and left digital "tracks" all across the web.
Anonymous Iberoamerica listed Spaniards known by the nicknames "Pacotron" and "Troy" among those arrested. Interpol detained the hacktivists in Argentina, Chile, Colombia and Spain as part of Operation Unmask, launched in mid-February after a series of cyber-attacks against private and governmental targets.
The international police agency said that about 250 items of IT equipment and mobiles were seized during searches of 40 premises across 15 cities. The suspected hackers are aged 17-40.
Anonymous took down the website of Interpol briefly and threatened to expose individual agents belonging to the agency.
Chile's chief prosecutor, Marlis Pfeiffer, told Associated Press that authorities had released the five people arrested as part of the Interpol swoop in the country.
An Argentine police official said that 10 adults were still being detained.