Egyptian authorities have detained 29 people, including 13 foreigners, accused of running an online cryptocurrency scam that defrauded thousands of investors, state media reported Sunday.

The network pocketed about $620,000 at the expense of its victims in the country now battered by an economic crisis and rapid inflation, the report said.

The group ran the online platform "HoggPool" which promised its clients "financial gains after having lured them by fraudulent means", said a statement released by the prosecution service late Saturday.

The scheme promised large profits from crypto-currency mining and trading services, for fees charged at an attractive foreign exchange rate.

"They sold people a computer tool: you paid 4,000 Egyptian pounds for it, and you earned 30,000 pounds. You paid 100,000 and you earned a million," said TV talk show presenter Amr Adib.

Launched in August, HoggPool abruptly ceased operations in February and vanished with the money, the state-run daily Al-Ahram reported.

Authorities said the network was planning to launch a new platform called "Riot" when they were arrested.

The interior ministry said 16 Egyptians and "13 foreign nationals of the same country", which was unidentified, had been arrested. Officials also seized 95 mobile phones, 3,367 SIM cards and 41 foreign bank cards, it said.

Egypt, the Arab world's most populous country with nearly 105 million people, is suffering one of its worst-ever economic crises.

In one year the Egyptian pound has lost half its value against the dollar.