OSAKA — Two Myanmar sailors were caught last month using Myanmar coins to buy cigarettes and collect change from a vending machine in Osaka, police said Thursday.

The suspects, aged 30 and 32, were reportedly using 1 kyat coins, which are similar in size and weight to 500 yen coins. But the Myanmar coin has a value of about 1 yen.

Police said the suspects were caught May 16 in Osaka’s Minato Ward after officers received a tip from passersby. The sailors were apprehended while putting the coins into the cigarette machine, police said.

They were found with 25 of the coins, 14 packs of cigarettes and 8,580 yen in change, according to investigators.

However, police decided not to bring charges against the sailors, and they were allowed to return to Myanmar.

From 1997 to 1999, there were 14 reported cases of people fraudulently using kyat coins in Japan, according to the National Police Agency. Arrests were made in two of the cases.

Unlike other foreign coins used for defrauding vending machines, the Myanmar coins are so similar in size and weight to 500 yen coins that they require no alterations.

Forgers using the South Korean 500 won coin, by contrast, drill depressions in its surface to reduce its weight to that of the 500 yen coin. The South Korean coin is worth about 50 yen.

The other coins used in the 14 reported cases of fraud are the Hungarian 20 forint, equivalent to about 10 yen, and the 50 rial coin from Iran, worth about 3 yen.

To counter the rising number of cases of vending-machine fraud, the Finance Ministry plans to introduce in August a revamped 500 yen coin made of a new type of alloy.