The male suspects, aged 26, 59 and 60, were arrested while attempting to steal for a second time at the fair.
One of the exhibitors from Kuala Lumpur at the fair lodged a report on Sept. 29 stating that a bag containing 54 expensive watches, 40 diamond rings and 20 crystal necklaces was missing.
City Police Chief, ACP Azizan Abu Taat, who confirmed the arrest, said the complainant was checking in at the hotel registration counter and had placed the bag on the floor earlier.
He disclosed that the complainant only realised the bag missing after completing the latter's registration.
Based on a tip-off, police detained the suspects at about 6.30pm while the men were at the fair, he said, adding that investigations are ongoing.
It was also learnt that the fair organisers placed Closed Curcuit Televisions (CCTVs), which enabled them to spot the suspects, after the incident earlier.
They were caught with the help of the Magellan security personnel.