An underpants thief is terrorising plane passengers in Papua New Guinea.

Women travelling with the national carrier Air Niugini are fed up with one or many baggage handlers nicking their knickers.

Four women, who wish to remain nameless, told AAP how their best undergarments were stolen from luggage when travelling on domestic flights leaving the capital Port Moresby.

One tourist on a brief stay in PNG said her bag’s lock was broken and the only items missing were g-strings and lace hipster briefs.

“I could not believe it. I was shocked, it’s just too creepy,” she said.

“I have travelled all around the world and this is the first time something like this has happened,” she said.

Another woman visiting her mother in Lae, on PNG’s north-west coast, discovered her pink panties were gone.

“What makes it weirder is that I had much more valuable items to steal than my underpants,” she said.

Another woman said Air Niugini had asked for a statuary declaration and receipts as proof when offering compensation for the stolen items.

“I was in the Highlands, Mt Hagen, of all the places in PNG, and had to ask the police for a stat dec to claim payment from Air Niugini for the lost items,” she said.

Air Niugini officials told AAP they would get to the bottom of the issue.

“We have spoken with frontline staff about missing luggage or stolen items.

“We are unaware of that particular item being targeted,” a spokeswoman said.