Under the new security restrictions for liquids, gels and aerosols (LAG), many Aussie travellers have been forced to surrender their duty free goods while connecting to another flight from Bangkok's Suvarnabhumi airport.

According to a report by The Nation, Thailand's duty-free giant King Power has lost more than 150 million baht in sales of alcohol and perfume since airlines have introduced the ban to carry liquids onboard in line with international regulations.

THAI Airways' Marketing Executive, Kevin Fisher has advised that passengers travelling in transit through Thailand should refrain from purchasing duty free items. Rather, duty free items should only be purchased on the final leg of their journey.

While staff selling duty free items onboard THAI and at duty-free stores try their best to inform passengers of the ban, some passengers still assume it is okay to purchase goods if they are transferring through Thailand - only to be caught out when they get to the boarding gate.

For travellers who insist on purchasing duty free in Australia, THAI advises on its website that passengers should keep their purchases in a tamper-proof plastic bag with satisfactory proof of purchase (on the same day as the fight departure) displayed on the front.

But to be safe, Fisher recommends that travellers should make duty-free purchases on their way back to Australia or pick-up the purchases on their arrival at the airport.

According to Airports of Thailand board member, Chirmsak Pinthong, airports could be introducing a new system where passengers who buy liquid products from duty-free stores are issued with special seals and certificates that allow the purchases to be taken onboard.

However, until then, travellers should be wary of the ban.