The details are confusing (and reporters are getting arrested), so the articles are a little tough to follow. Some details from the articles by NYT, Al Jazeera, and BBC:
In Egypt, despite a near blackout on state news media, independent journalists set out to uncover the identities of the Egyptians detained on the plane.
A few independent media organizations published the names of the Egyptian defendants. Then an independent investigative outlet called Matsada2sh, which is Arabic slang for Don’t Believe It, reported that three of them appeared to be former or current security officials, including a police officer, a military general and a former military attaché at Egypt’s embassy in the United States.
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Through open-source data and online flight trackers, matsada2sh was able to reveal a trail of suspicious flight paths in which the plane, a high-speed corporate Bombardier, appeared to fly unfettered across multiple locations.
The plane appears to have made 361 round trips in two years, usually in and out of Cairo, to various destinations.
It even made flights to Tripoli and Benghazi, two cities on either side of the ongoing conflict in Libya, within days of each other.
On another occasion, it took off from Cairo and stopped over in Tel Aviv, and Doha, Qatar, before returning to the Egyptian capital.
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at first police said they had found $11m in cash. This, he went on, was later downgraded to around $7m before finally settling on the sum of $5.7m.
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The gold bars were particularly puzzling.
It turned out that, as well as gold, they were made from a mixture of copper, nickel, tin and zinc. All that glitters is clearly not gold.
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A think-tank called the Egypt Technocrats, made up of independent Egyptian professionals living around the globe, claims there are more than 300 secret companies inside Egypt involved in money laundering operations.