The aide, whose identity was not disclosed, was caught by a team of Delhi Police's Special Cell and UP's Anti Terrorist Force, they said.
He is understood to have helped Jabbar alias Syed Amir Ali, the alleged Pakistani spy who was arrested from Delhi airport on Saturday, to procure a passport and driving licence using forged documents.
Police claims that Jabbar, who was staying in Shahdara area in the guise of a man hailing from Lucknow, belongs to Karachi.He was working as a technician in a mobile phone repair shop in Mansarovar Park in north-east Delhi.
Jabbar was caught while trying to board a flight to Damman in Saudi Arabia allegedly using a fake passport, he procured from Lucknow.
Investigators have learnt that he entered India through Nepal five years ago. He stayed in Lucknow during 2005-06.
After Jabbar was handed over to Delhi Police's Special Cell by immigration officials who arrested him, police personnel from the capital had gone to Meerut and Lucknow to investigate how he managed to obtain a fake passport and driving license.
Investigators also claimed that they had seized maps and documents of Delhi Cantonment, Meerut Cantonment and Hindon airbase from him.