Having tracked him down, the intelligence coalition arrested him and his nephew Gıyasettin Baybaşin in a mansion in Lieshout, Netherlands on 27 March 1998 in a joint operation code-named Black Tulip.

Baybaşin was once referenced in the Valley of the Wolves, Turkey's most popular TV series about the mafia.

[1][2] In the early 1970s, his uncle Mehmet Şerif Baybaşin started producing drugs by refining heroin in an isolated village in Lice.

[6] On 23 May 1984, he was arrested in Dover, United Kingdom for smuggling drugs internationally on the basis of a fake passport and sentenced to 12 years imprisonment.

[7][8] The Kısmetim-1 which was surrounded by the USS Briscoe-backed Underwater Offence (SAT) team, allegedly carrying ~6,800 lb (3,100 kg) of base morphine to be smuggled to Turkey, was sunk by its crew in 1992.

[9] The captain, who admitted after police interrogation that he received the order from Baybaşin, did not accept the allegations about the presence of drugs on board.

[14][15] His strict confidentiality was difficult to unravel and was discussed with the Dutch (AIVD), Belgian (GISS), and German (BND) intelligence services.

[14][13] It was difficult to wiretapping to him because he kept changing his telephone number, did not share it with anyone except relatives, and used cryptic phrases in his conversations.

[16] Baybaşin was talking to a relative and told him what he was thinking on the phone: "I've a strange feeling, as if we're resting and they are following us.

[17][19] Ton Derksen, a Dutch professor emeritus, got access to the telephone recordings which were presented as evidence.

[24] On 23 March 2004, a psychiatric report found that he had developed various mental problems including chronic post-traumatic stress disorder, depression, and a strong tendency towards somatisation during his detention in the maximum security prison.

[23][16] A search of Baybaşin's house in Green Lanes (London) revealed clues that torture had taken place there.

[25] This "torture cell", located on the upper floor of the house, had a 12 inches (30 centimetres) thick soundproof door, and three layers of glass insulation.

[28][29] Baybaşin was held responsible for the murder and disposal of the body of Murat Kartal, a Turkish gangster and former friend with whom he had a conflict of interest.

[30][31] Kartal's body was later found in 2021 by chance during excavation work in the Pınarbaşı neighborhood of Büyükçekmece, Istanbul, with his clothes on and concrete thrown over him.

[45][46][47][48] According to the reports of the Dutch police, in the same year he owned movable and immovable property,[46] but the licences and title deeds of the properties were registered in the name of his relatives, not him, and most of them could not be confiscated:[48][49] It is estimated that he invested the rest of his fortune in touristic resorts, luxury hotels, and nightclubs on the Mediterranean and Aegean coasts.