The smugglers told the migrants that they would take them to Europe for $10,000 (8,400 euros), with the money to be paid after they arrived, according to Hurriyet daily.
Some of those found on Monday had been tortured, the newspaper added.
The migrants had reportedly hoped to reach Europe via Greece or Italy, giving a code to the smugglers to access the money upon reaching Europe, Hurriyet said.
However, the people-smuggling gang mainly made up of Pakistanis demanded the $10,000 upfront and told the migrants chained in Istanbul to call their families to tell them they had reached Europe already and to transfer the money, the daily said.
Hundreds of thousands of migrants including Syrians, Iraqis, Pakistanis and Afghans have entered Europe in recent years.