International criminal Charles Sobhraj has appeared in a Nepalese court in connection with the killing of two tourists in Kathmandu nearly 30 years ago.
Sobhraj allegedly confessed his crimes to an Australian author
The court has permitted Sobhraj, a French national, to be kept in police custody until Friday.
He was arrested at the Yak and Yeti casino in the Nepalese capital on Friday and also faces charges of violating immigration laws.
Police say he used Dutch and French passports to enter Nepal and that one of the passports is suspected of being forged.
Sobhraj, 59, a Vietnamese-Indian by birth, was released from a Delhi jail in 1997 after serving 21 years and deported to France.
He is suspected of involvement in up to 20 murders in a number of countries across Asia in the 1970s.
However, despite all the allegations against him, Sobhraj has never been convicted of murder.
Known as The Serpent, Sobhraj's criminal career has spawned books and reports of a movie deal.
India deported Sobhraj in 1997 after he had spent 21 years in jail
He is alleged to have preyed on backpackers in Thailand during the 1970s, often drugging them and stealing their cash and passports.
The killings became known as the Bikini murders after American pilgrim Jennie Bollivar was found dead in her bikini in the Gulf of Thailand.
By 1976, the death toll had reached double figures and Sobhraj was wanted in at least three Asian countries.
In Nepal, he was suspected of killing Canadian Laddie du Parr and American Annabella Tremont, whose charred bodies were found outside Kathmandu.
Sobhraj was finally jailed for 10 years in Delhi in 1977 for drugging an entire busload of tourists at the city's Vikram Hotel.
While in Delhi's Tihar jail, he allegedly told Australian author Richard Neville about his murders, thefts and confidence tricks.
Mr Neville later wrote the book The Life and Crimes of Charles Sobhraj, the contents of which Sobhraj has challenged.
Neville says Sobhraj staged a breakout from Tihar in 1986 by drugging the guards.
He was caught 24 days later in Goa and earned a further sentence in Tihar, sufficient to pass the time limitation on the murder charges in Thailand that he feared being extradited to face.
Sobhraj has been keeping a low profile in France since deportation from India in 1997.
He was thought to be pursuing business interests in Nepal.