The arrests came after police were called to 700 block of Lancaster Avenue in the Devon section of Tredyffrin Township around 4:00 p.m. on Friday for a report of two suspicious people.
Patrol officers stopped an unidentified person who admitted to using the sexual services of a prostitute in an encounter that was allegedly arranged on the internet.
Police say a female suspect was later identified as 24-year-old Jacquelyn Stahley of Portland, Oregon.
As the investigation continued, police say 29-year-old Jamaal Lambert, also of Portland, Oregon, was arrested on related charges and possession of a controlled substance.
Both Stahley and Lambert were arraigned and ordered to be held on $15,000 cash bail.
A preliminary hearing is scheduled for Wednesday.
Police did not disclose if the person who admitted to using the services of a prostitute will be charged.