COLOMBO, Sri Lanka (AP) — Sri Lanka's diamond-swallowing saga took an unexpected turn Tuesday when police revealed the stone swallowed by a visitor at a gem exhibition was a fake and they are searching for the real stone valued at $13,000.

Police arrested Chou Wan, 32, after a gem owner complained a man had swallowed his 1.5 carat diamond at a jewelry show in Colombo last week. An X-ray taken at a hospital showed the diamond and Chou was given a laxative so the gem could be recovered. The National Gem and Jewelry Authority, which regulates the gem industry, then was asked to inspect the diamond concerned.

Police spokesman Ajith Rohana said the authority informed police the diamond Chou swallowed was fake and had no financial value. He said investigators suspect another Chinese man seen with Chou may have the real diamond worth 1.8 million Sri Lankan rupees ($13,636).

Exhibitor Suresh Wijekoon said two Chinese men were behaving suspiciously at his stalls and he suspected they were trying to switch fake stones to steal the real diamonds. He said one man swallowed a diamond before he alerted the police while the other ran away.

Sri Lanka does not mine diamonds but is renowned for other highly treasured gems. Facets Sri Lanka 2012 is the island nation's annual largest gem and jewelry exhibition and it attracts a large number of local and foreign buyers.