He is identified as Rashid Rauf. Both men were picked up in the cities of Lahore and Karachi last week.
They were among seven people arrested in Pakistan.
Intelligence officials later said more Pakistanis had been arrested in the east of the country in connection with aircraft terror plot.
No immediate government confirmation was available regarding the latest round of arrests, but officials have said the seven arrested earlier provided important information about the UK plot.
UK police are questioning 23 people over the alleged plot to attack planes flying from the UK to the US.
Another person arrested was released without charge on Friday night.
Rashid Rauf is thought to be related to Tayib Rauf, 22, of Birmingham - one of those arrested in Britain.
Airports in India and Pakistan have tightened security.
"Pakistan played a very important role in uncovering and breaking this international terrorist network," Tasnim Aslam, the spokeswoman for the foreign ministry said.
Pakistan says the UK police operation was closely co-ordinated with Pakistan and the US.
The Home Office refused to confirm reports that Thursday's anti-terror operation in the UK was triggered by the interception of a decoded message sent by a suspect in Pakistan, which gave the go-ahead for the attack to take place.
A spokesman said: "We work closely with the government and agencies in Pakistan on a range of issues.
"We are very grateful for the help and co-operation we have received from our international partners, including Pakistan."
On Thursday the founder of the banned militant group Lashkar-e-Toiba, Hafiz Mohammed Saeed, was placed under house arrest.
However, intelligence sources say the move was not connected to the UK plot.
Armed police have been deployed in many airports and passengers are being subjected to increased screening and hand baggage checks in India and Pakistan.
Security has been tightened at the Delhi airport
The alleged plot is said to have involved smuggling liquid explosives onto planes in hand luggage.
Sources told the BBC the "principal characters" suspected of being involved in the plot were British-born, and some have links to Pakistan.
BBC security correspondent Frank Gardner says the decision to arrest a large number of suspects in Britain was directly linked to similar arrests a few days ago in the Pakistani port city of Karachi.
The Associated Press quoted an unnamed Pakistani intelligence official as saying an Islamic militant arrested near the Afghan-Pakistan border several weeks ago helped in "unearthing the plot".
"The major work was done by the British agents, but they got a major clue from Pakistan," the official said.
Pakistan has been a key ally of the US in its "war on terror", although this has drawn widespread opposition at home.
Source:BBCGüncelleme Tarihi: 20 Eylül 2018, 18:16