A man from Whitley Bay has flown from Prague to the UK on the wrong passport after accidentally taking his friend's and leaving him stranded in the Czech capital.
Allan Poole, 43, travelled from Prague to Newcastle via Amsterdam on a KLM flight.
The passport was checked or scanned at least four times during the journey but the mistake was never flagged.
Border control agents who checked his passport when leaving the Schengen area at Schiphol airport, Amsterdam, and UK immigration officials who checked it when he arrived home did not identify the mistake.
Watch Gregg Easteal's report here:
KLM staff at the boarding gate in Amsterdam also did not notice the name on his boarding card did not match the passport.
Mr Poole's friend, Steve Vincent, 43, also from Whitley Bay, is now stranded in Prague until the British Embassy provide him with an emergency passport.
A spokesman for the British Embassy in Prague said it was not unusual for people to travel on other people's passports.
"People do travel on (the wrong passport), they don't get checked when they come out and stuff like that," the spokesman said.
"It's quite common actually, to be honest with you, people do travel on other people's passports accidentally, it does happen."
"It even happens in the UK, people come out on perhaps a child's passport that's sometimes not checked, it does happen.
"Border controls sometimes don't look, I don't know for what reason."
"Our officers are also involved in the training of airline staff and immigration officers overseas to spot false documents to stop people from even beginning their journey to the UK. "Between April 2010 and December 2018 more than 159,000 people were refused entry to the UK, including those refused for travelling on invalid documentation."
Mr Vincent tweeted KLM airlines asking what they are going to do about the issue after they let Mr Poole travel on his passport.He said: "Hey KLM you let my friend travel from Prague to Newcastle on my passport (after we swapped by mistake).
"You shouldn't have let him on the plane. I'm trapped in Prague. What are you going to do about it?"
Mr Poole said no-one noticed he was travelling on the wrong passport and he only realised himself when he got back to the UK.
Speaking to The Independent, he said: "I even failed the e-passport gate in Amsterdam and went to a booth and was waved through.
"At Newcastle control they looked at the passport and waved me through."
The pair were on a weekend trip to the city when they accidentally swapped their passports while checking into their accommodation.
Mr Vincent said in a tweet: "We were sober when we accidentally swapped. Just arrived, had to fill out a form with passport details, left both on the table and one of us picked up the wrong one."
The British Embassy spokesman said it would assist Mr Vincent as he would not be able to return to the UK without an emergency travel document.
It normally takes two working days to process and costs £100, they added.