Alex Lawton thought he was just having a bit of a laugh with his mates, but instead he quickly found himself trapped in a nightmare scenario overseas.
The 26-year-old skateboarder from Brisbane, who travels all over the world due to his work, recently spent two weeks in Shanghai for a filmed skating tour when trouble struck.
The trip had started off pretty innocently; Mr Lawton had heard about some great 'hidden' markets that sold cheap items, so he went for a look and snapped up a bargain in the process.
"Like a lot of tourists, we went to one of these markets and I ended up buying a torch taser to play pranks on my friends," Mr Lawton told news.com.au. "It looked like a toy and I thought it was just a bit of harmless fun."
However, on his way back to Australia - via Hong Kong - things turned sour for the unsuspecting tourist.
"On the way home I packed it in my bag and thought nothing of it when I checked it in at the airport - I didn't see any signs saying you couldn't fly with them.
"We flew via Hong Kong, and while we were in transit at Hong Kong Airport, I was called off the plane and was asked if I was carrying a gun in my bag. Initially I thought it was all a big joke as they rummaged through my bag on the tarmac, I just laughed, thinking that there was nothing inside that would cause a problem.
"Then one of the officials pulled out the torch taser. Again - I laughed and said that it was just a toy! However, it quickly turned serious, when they told me that it was an illegal weapon and they arrested me on the spot.
"I couldn't believe it and at first I was just in shock. I thought they had made a mistake."
It turns out that under Hong Kong law, stun guns (including torch tasers) are classified as banned items even for those simply transiting through the airport, and offenders could be fined up to HK$100,000 ($18,619) and imprisonment for up to 14 years.
Mr Lawson ended up being detained at the airport while he awaited a trial.
Communication with officials proved problematic.
"They brought me into the airport and held me in a room for what felt like forever. At first I tried to ask what was going on, but it was really tough to understand them because we didn't speak the same language ... It was pretty scary.
"During the night, officials kept coming in and out of the room asking me if I had any money on me. Alone, confused and scared, it all sounded quite dodgy to me - like what happens in movies - but I did later find out that a fine is part of the standard sentence for carrying an illegal item."
He was also asked to fill in several forms and said while he had no idea what they were for, he complied in the hope of being released.
The next morning he was taken to a police station where he was allowed to call his mother, who assured him everything would be OK and said she'd help organise the payment of the fine if needed.
"I was pretty agitated though - at this point I had been held on my own for nearly 24 hours, fearing the worst."
Next up was an appearance in court, where he was told to present his case - alone. He pleaded guilty and apologised.
"I told the judge what happened and pleaded with him that I had no idea the torch taser was illegal or in any way harmful and that I thought it was just a toy. It was such an incredible relief when I was just given a fine (of $457). All I wanted to do was just get on a plane home and end this nightmare."
But there was one final catch - before being allowed to go, he had to provide DNA samples to the police.
He was given a criminal record, but as it's a minor offence he is allowed back in the country. Following his experience, Mr Lawton decided to share his story in order to warn others to be better prepared about carrying restricted items overseas.
"Looking back, I know that what I did wasn't the smartest move. Although I thought to myself at the time that what I was doing wasn't wrong, next time I buy anything abroad I'll definitely check that it's legal in every country I'm travelling to and through - even if it looks like a toy.
"I wanted to share my story so that what happened to me doesn't happen to anyone else. I definitely won't make the same mistake again - it was one of the craziest experiences of my life!"