During preliminary questioning, Faesal said he was taking a connecting flight to London from Istanbul, the officials said.
After being detained at the Delhi airport, he was again detained under the PSA on his arrival in Srinagar, the officials said.
Faesal had criticised the "unprecedented" lock-down in the Valley with its eight million population "incarcerated" like never before post the removal of special status to Jammu and Kashmir, provided under Article 370.
He is among the latest political leaders who have been placed under house arrest.
Former Jammu and Kashmir
chief ministers Farooq Abdullah, Omar Abdullah
and Mehbooba Mufti were detained after the Centre revoked the special status and announced that the state be bifurcated into the territories of Jammu and Kashmir, and Ladakh.
The Jammu and Kashmir authorities last week airlifted a fresh batch of 20 "potential troublemakers" from Srinagar to Agra as a precautionary measure in the wake of constitutional changes made by the government.
Among those airlifted include president of Kashmir High Court Bar Association Mian Qayoom.