An armed man stole at least $1.5m (£950,000) in casino chips from a craps table at the Bellagio resort in Las Vegas before escaping on a motorcycle, police have said.
The suspect entered the casino at 0350 local time wearing a motorcycle helmet and walked directly to the table.
The man may have robbed the Las Vegas Suncoast Casino last week, police said.
Strict controls over Las Vegas casinos may make it difficult to cash in the chips anywhere other than the Bellagio.
Chips are generally unique to specific casinos and are typically not interchangeable.
"Casino chips are not like cash - at some point they must be redeemed," MGM spokeswoman Yvette Monet told Reuters news agency.
MGM Resorts, which owns the Bellagio, captured video footage of the suspect.
Police said that if the same culprit was responsible for the Las Vegas Suncoast Casino robbery, he may have netted less than $20,000 (£12,000) in chips during that heist.
The incident at the Bellagio was the 10th casino robbery in Las Vegas this year.