The diamond, valued at $20 million (£15 million), was allegedly stolen from a vault of a Dubai-based money transfer company on May 25th.
The diamond was also recovered after it was again found being smuggled into Sri Lanka by sea in a shoe box by a relative of the suspect, who was detained as well.
The suspected thief, a guard working for the company, has been arrested and is detained in Dubai.
He is believed to have stolen the diamond and given it to a relative to take out of the country.
According to the Commander-In-Chief of the Dubai Police Force, Abdullah Khalifa Al Merri, the employee had managed to break through three separate security systems to get into the vault.
One of the security systems in place requires three guards to open the last gate simultaneously with a key, a pin and an electronic code that changes automatically every minute.
The commander says they believe the suspect planned the robbery for 14 days and his security background helped him.
Al Merri said the operation to recover the rare 9.33 carat blue diamond named ‘Brilliant’ was closely followed by the prince of Dubai, Shaikh Hamdan Bin Mohammad Bin Rashid Al Maktoum.
He told local media that it was thanks to direct orders from the prince and the PM of the country that they were able to what was necessary to solve the case, which was done at record speed.
The guard was hiding out in a neighbouring emirate according to official sources and had stopped communicating with his relatives.
Al Merri said: “He thought he would be able to hide out for a bit then come back to Dubai and live the life of a millionaire.”
The police chief added that the Dubai Police will always “trump the criminals”.