Girish Pathak and his wife Anamika were arrested by the Crime Branch team of Delhi police from Sarai Kale Khan on Thursday, after police got a tip off that they would be coming there to board a bus.
The Bihar police has been informed about their arrest.
Anamika used to work as a receptionist at the hotel of the victim's father and later got her husband a job as driver for the family, Additional Commissioner of Police (Crime) Ashok Chand said.
They took him to a secluded place in Aara, Bihar, from where they made ransom call and demanded Rs 2 crore for the safe release of the boy.
"The boy's family had agreed to their demands but before they could succeed in their nefarious plans, local police raided their hideout and rescued the boy and arrested three persons Abhishek, Vinay and Pardeep. Girish, along with Anamika, managed to escape from there and since then both were evading their arrest," Chand said.