Elena Ciochina was spotted in Madrid at the weekend following a public appeal for help and the man was arrested for abduction.
A manhunt was launched after a European Arrest Warrant had been issued for a Romanian 27-year-old accused of abducting the teenage girl from East London.
British police asked for help from their Spanish counterparts to find Ionut Gheorghe after he went on the run with the teenage girl.
The girl, also Romanian, disappeared from her home in Newham, east London, on the afternoon of Saturday 23rd July, Scotland Yard said.
Gheorghe was spotted on CCTV taking cash out of machine in Enfield North London earlier that afternoon.
Police believed the pair had fled the UK and were making their way to the Guadalajara area of Spain, to the north east of Madrid.
The metropolitan police described Elena as “1.75m tall, with waist-length black hair. She was wearing a black Tshirt, black jogging bottoms and black plimsolls. It is believed she is in possession of a Romanian identity card.”
The statement said Georghe was “white, about 1.70m tall, of heavy build with short light brown hair, he was last seen wearing a white T-Shirt, dark shorts and dark coloured flip flops.”