The man trying to cross into India through the Kakarbhitta border check post in eastern Nepal's Jhapa district caught the attention of police though he presented a valid passport. It was a Nepali passport, but he could not speak a single word in Nepali.
The suspicious policemen handed him over to the authorities in neighbouring Sunsari district as his passport showed it had been issued from there.
After the arrest early this month, police say investigations are pointing to the arrested man being Pakistani national Ashraf Ali, who is wanted for terrorist activities in his own country and has an Interpol alert issued for his arrest.
While police remain tightlipped about Ali, media reports say he had been living in Nepal under fake Nepali citizenship acquired after bribing district officials.
Police on Monday arrested a municipality official on the suspicion that he had recommended a Nepali passport for Ali, who had been living in border towns close to India: Inaruwa, Duhabi and Biratnagar.
When he was arrested, Ali was trying to cross into India and from there proceed to Pakistan.
Last month, at the same border check post, Nepal police arrested another notorious international criminal wanted by India and Bangladesh.
Subrata Bayen, caught in an arms smuggling case in India's West Bengal state last year, was soon out on bail when he fled the country and headed towards Nepal.
Nepal police also found a Nepali passport on him.
Bayen is currently in eastern Nepal's Bhadrapur jail while investigations are on.
Last month, yet another wanted man who had made Nepal his home to avoid being arrested by the police of his own country was arrested as he tried to sneak back.
American Brenice Lee Smith was nabbed at the San Francisco International Airport as he arrived there on a flight from Kathmandu.
The 64-year-old is suspected of being part of the Brotherhood of Eternal Love, a Hippie gang of drug dealers and users that was founded in the 1960s. Smith had been living in Nepal posing as a Buddhist monk.
The deteriorating law and order system due to continuous political instability for nearly 13 years, corruption in the bureaucracy that enables criminals on the run to procure passports and other legal documents easily and the open border with India have contributed to a growing number of criminals from other countries heading for Nepal where they can lie low in safety.
There are also allegations that some politicians are involved in providing a safe haven to criminals on the run.
Indian don Babloo Srivastava wrote in his fictionalised memoirs that Nepali lawmaker Mirza Dilshad Beg provided safe houses for terrorists from Pakistan and their safe passage from Nepal to Thailand.
Beg was murdered near his own residence in Kathmandu in 1998 in what was believed to be gang warfare.
Besides terrorists, arms and drug smugglers and counterfeit Indian currency dealers, Nepal is also increasingly becoming a haven for western paedophiles.
In 1999, Nepal police arrested French citizen Jean Jacques Haye and British national Christopher R Fraser for paedophilia and running a child pornography racket internationally. Both ran child care centres in Kathmandu and abused the inmates.
Though Haye was deported, he returned to Nepal and lived there quietly till his arrest once again this March when a childcare organisation tipped off police.