German police have shut down one of the world’s largest illegal online markets in the so-called dark web and arrested the three men allegedly running it, prosecutors said on Friday.

The “Wall Street Market” (WSM) site enabled trade in cocaine, heroin, cannabis and amphetamines as well as stolen data, fake documents and malicious software.

The encrypted platform had more than 1m customer accounts, over 5,000 registered sellers and more than 60,000 sales offers, according to Frankfurt prosecutors and affidavits filed by US prosecutors in a federal court in Los Angeles.

“WSM operated like a conventional e-commerce website, such as eBay and Amazon. However, its sole existence was geared to the trafficking of contraband,” US prosecutors said.

Three German men alleged to be administrators of the site were arrested, while a fourth man – a Brazilian who, prosecutors said, acted as an online mediator for the website – was arrested in Brazil.

Klaus-Martin Frost, Jonathan Kalla and Tibo Lousee are accused of running Wall Street Market for nearly three years, providing a darknet platform for the sale of narcotics, counterfeit goods and hacking software to 1.1 million customers.

The Germans, known to investigators by the monikers “coder420”, “Kronos” and “TheOne”, also face charges in Germany.

“While they lurk in the deepest corners of the internet, this case shows that we can hunt down these criminals wherever they hide,” US attorney Nick Hanna said in a written statement announcing the charges.

Among the site’s top vendors were two people based in Los Angeles: “Ladyskywalker”, who sold opiates such as fentanyl, hydrocodone and oxycodone, and “Platinum45”, who dealt in methamphetamine, oxycodone and a combined amphetamine prescription drug marketed as Adderall.

The people operating those accounts have also been arrested, according to the criminal complaint. Their names have not been made public.

Launched in 2016, WSM grew over the past three years to be the largest darknet site after the 2017 shutdown of the notorious AlphaBay and Hansa marketplaces.

The site was accessed through the encrypted Tor network to shield customers from detection and transactions were made with the cryptocurrencies bitcoin and Monero.

It offered interfaces in six languages – English, French, German, Italian, Portuguese and Spanish – and numerous separate categories for merchandise, including drugs, jewellery, equipment and support for credit card fraud, software and malware, among others. One vendor category, according to the court filings, was simply named “fraud”.

Like legal online marketplaces, buyers could search by product, product popularity, vendor ratings, payment type and price. The operators allegedly received commissions of between 2% and 6% of the sales value.

The police operation started after Finnish authorities shut down the illegal Tor trade site Silkkitie (Valhalla) earlier this year, said Europol. This led some Finnish narcotics traders to move to WSM.

In April, the WSM administrators were apparently alarmed at the sudden surge of customers and, the court documents said, enacted an exit plan that involved freezing the escrow accounts and customer wallets and taking out all the virtual currency held in them at the time – estimated at $11m (£8.3m).

That spurred investigators to act, and on 23 and 24 April they arrested the three German suspects, aged 22 to 31, in the states of Baden-Württemberg, Hesse and North Rhine-Westphalia.

They also seized servers, more than €550,000 (£470,000) in cash, and hundreds of bitcoin and Monero, as well as several vehicles and a gun.