A suspicious incident occurred on the first day of the BaselWorld watch and jewelry show, which is running through March 31.

Four men, who appeared to be from the Far East, entered the booth of Solo Diamond, a US diamond company. The owner identified one of the four as the suspect who allegedly switched a piece of cubic zirconium for a four-carat diamond at last year's BaselWorld. The diamond dealer told his partner to keep an eye on the men and went to find security.

The owner asked representatives of the Malka Amit armored company for assistance. They arrived at the booth to find that the four men had gone. Two were spotted at other booths, but the man who allegedly stole the diamond last year wasn't to be seen.

Representatives of Malka Amit followed the two who had been identified to the restroom and alerted exposition security, who searched the two suspects but didn't find anything. However, a search of the restroom stalls turned up a number of cubic zirconium stones of different sizes. The two men were detained for questioning.