Rapid Action Battalion arrested Diamond World managing director Dilip Kumar Agarwala on early Wednesday.
RAB Media Wing in a text confirmed the news and said that Dilip was arrested in Gulshan area in the capital.
Earlier on Monday, the Criminal Investigation Department launched an investigation against Dilip over allegations of laundering money and smuggling gold and diamonds.
CID said that Financial Crime Unit of the department had been tasked with conducting the investigation.