Staff have allegedly been planting bullets into the bags of unsuspecting passengers at Philippines’ Manila Airport.

Legislators have called for an investigation into the supposed racket that extorts money from passengers by threatening to charge or arrest them for carrying illegal ammunition, the BBC reported.

“This is becoming an international embarrassment,” said Sherwin Gatchalian, a member of the tourism committee in the House of Representatives, according to the BBC. He warned that the offenders were “not afraid to prey on foreigners.”

A Filipino worker and Japanese tourist were the latest passengers to be detained in the swindle at the Southeast Asian nation’s main gateway. Other targets have reportedly been taken to court for refusing to pay fines.

They also come ahead of the Philippines hosting US President Barack Obama and other world leaders for the annual Asia-Pacific Economic Cooperation summit on November 18.

Responding to the media frenzy, Transport Secretary Joseph Emilio Abaya said the scam had been “blown out of proportion” but confirmed cases had been filed against security officers over two alleged extortion attempts.

“A single case of any passenger ... charged or victimised by planting (bullets) is unjust ... it merits full government attention,” Abaya told reporters.

Abaya said one of the cases involved a complaint from an American. Although he did not give details on the American, local press have widely reported allegations from a US missionary who said a bullet was planted in his luggage at Manila airport.

Security personnel demanded 30,000 pesos (A$900) or they would press charges for illegal possession of live ammunition, media reports cited the American as saying.

He refused and was charged, then released on bail, according to the reports. A US embassy spokesman declined to comment on the case.

In the Philippines, possession of live ammunition is punishable by six to 12 years in jail.

Philippine media outlets have carried reports of many passengers claiming to have had bullets planted in their luggage, with security personnel then demanding cash to avoid being charged and allowed to catch their flights.

The scam has apparently built off a tradition for some Filipinos to carry bullets as lucky charms, so it is not unheard of for people to carry them in their bags.

In its advisory, the United Nations warned its employees to lock their luggage, never keep bags out of sight and consider wrapping them in plastic, two UN staff based in Manila told AFP.

When asked about the advisory, a spokeswoman at the United Nations Information Centre in Manila declined to comment.

Corruption is a major problem throughout all government institutions in the Philippines.

Here are some other travel scams to watch out for:

CHINA’S TEAHOUSE SCAM

Australians have been the target of a number of scams in China, including being drugged and robbed after accepting offers of food, drink or transportation from strangers; and the increasingly common “teahouse scam”.

According to DFAT, this is how it goes down: “An increasing number of tourists are being approached and invited for a drink at a teahouse nearby for an number of reasons including ‘to practice English’. Afterwards the tourist is presented with a vastly inflated bill and is not permitted to leave until they pay the bill by credit card. Physical violence, including serious assault, and credit card skimming or duplication has occurred.”

TUK-TUK TRICKERY

This is most prevalent in Thailand, but common throughout Southeast Asia in general. A tourist may ask the driver to take them to a particular hotel, temple, or shop and he’ll say it’s closed/burned down/no good, but he just happens to know a better one close by! The driver gets a commission for delivering the tourist to the destination, and it’s usually a poor imitation of the desired destination.

There’s even an entire fake tourist centre not far from Bangkok airport, according to travel safety specialist at Travel Insurance Direct Phil Sylvester: “Here the travel agents will say they’ve never heard of your booked hotel, but thankfully they can arrange a room at another establishment. Phew, how lucky — NOT!”

PAINT THE TOWN RED

In Argentina there’s a scam where someone will put paint (commonly a bright colour such as red) on a traveller’s bag, be very apologetic and try and wipe it off, then they grab it. If someone does this, hold onto your bag tightly and say you do not need help.

FAKE POLICE

Phony police officers are common in destinations such as Thailand and often falsely accuse travellers of committing crimes. For example, fake police may charge an on-the-spot fine for putting out a cigarette in public. Make sure to check the officer’s ID and contact the real police if in doubt.

BOGUS MONKS

Southeast Asia has its fair share of scams, but fake monks appear to pop up in almost all countries in the region. Dressed just like the real deal, these fake monks hit up tourist hot spots looking to collect “alms”, but they’re really after “financial donations”.

DUAL MENUS

A bar or restaurant will lure tourists in by providing a menu with cheap prices, then switching it with a pricier “tourist menu” once inside. It could see the bill double in the end. This scam is common in China and parts of southern Europe. Try to hold onto the menu first that is shown to you.

GYPSY BABY TOSS

Here a gypsy woman will approach travellers — usually single females — and toss what appears to be a young child (really a doll) into their arms. Fellow scammers then grab valuables from the traveller amid the confusion. Move away quickly if approached by gypsy beggars. They may also attack with newspapers.