Acting on a tip-off, tourist police raided a room at PB Hotel in Sukhumvit Soi 3 (Nana) and found a Nigerian man and a Thai woman inside.
Police searched the room and found five grammes of crystal meth and one gramme of cocaine alongside drug paraphernalia. The suspects were identified as Innocent Ogogua, 39, and Bussakorn Uttama, 37.
They were given urine tests for drugs and the results were positive, Pol Col Archayon Kraithong, deputy commander of the Tourist Police, told a news conference.
Police later found Mr Ogogua's passport had the missing visa stamp number A4055987 ― one of the 300 visa labels, issued by the Foreign Ministry to the Thai embassy in the Malaysian capital that were cancelled in August after they were found to have gone missing between January and July.
Mr Ogogua told police he bought his visa from a travel agency in Nigeria before entering Thailand earlier this year to export dried fish to his home country but did not succeed in the business.
He was charged with possession of Type-1 and Type-2 drugs as well as possession and use of a false official document.