It is no secret that a large proportion of the wealth accumulated by Dubai merchants comes from smuggling gold bullion (mostly from Britain), Swiss watches and Japanese cloth into Pakistan and...

https://www.economist.com/middle-east-and-africa/1970/06/06/golden-dubai

Gold flown from London’s bullion houses like Johnson Matthey and Samuel Montagu to the The British Bank of the Middle East and the First national Bank in Dubai played a significant part in making Dubai what it is today. Shipped out by Arabs, Pakistanis and Indians in dhows to Bombay and other ports like Kutch and Calicut in western India, it brought much wealth to the merchants and the larger business community of expatriates who had made Dubai, home. The narrative of oil in the Persian Gulf has largely overshadowed that of gold and underplayed its significance in linking Dubai to the international economy.

https://mei.nus.edu.sg/think_in/gold-smuggling-between-dubai-and-bombay/