- Lt Gen Faiz Hameed has been accused of abusing his power and raiding a private property development business during his time as head of the Inter-Services Intelligence (ISI) agency.
- It is incredibly rare for someone of Gen Hameed's rank to be arrested in Pakistan, and has sparked widespread speculation, with many linking the move to his close ties with former prime minister Imran Khan.
Pakistan's former spymaster - who was once tipped for the army's top job - has been taken into military custody.
Lt Gen Faiz Hameed has been accused of abusing his power and raiding a private property development business during his time as head of the Inter-Services Intelligence (ISI) agency.
It is incredibly rare for someone of Gen Hameed's rank to be arrested in Pakistan, and has sparked widespread speculation, with many linking the move to his close ties with former prime minister Imran Khan.
He led the ISI during Mr Khan's administration, from 2019 to 2021, before taking early retirement in December 2022.
The two were understood to be very close during that period.
The army's official statement said the arrest of Gen Hameed was ordered by the Supreme Court, and that the military had now started "the process of Field General Court Martial".
A court martial is a legal military hearing.
It also noted there had also been "multiple instances of violation" of the Pakistan Army Act since his retirement.
In an interview with the BBC, retired officer Lt Gen Talat Hussain described the move as "unusual" and predicted that many more arrests could follow.
According to some analysts, the arrest could be seen as part of the military's drive to hold people accountable within the institution.
The arrest of such a high-ranking officer signals that no one is beyond scrutiny, according to Senator Irfan Siddiqi, a close ally of former prime minister Nawaz Sharif.
However, others suggest that this may be more about settling old scores, with indications that the current army leadership and General Hameed did not see eye to eye.
There is also speculation that the arrest reflects a willingness to take action against those who were seen as backing Imran Khan, even if they were outside the political arena.
Mr Khan, who has been imprisoned for more than a year and is facing numerous charges, was once closely aligned with Pakistan's military leadership.
Opposition figures have previously accused Gen Hameed of being responsible for "selecting" Mr Khan for office, and was apparently so confident he was going to be named army chief he boasted of it, according to the BBC's former Pakistan correspondent.
Mr Khan's PTI party has appeared to shrug off speculation the arrest could be linked to them, with chairman Barrister Gohar Ali Khan describing the military’s actions as an internal matter.
The government has welcomed the arrest.
Gen Hameed could not be reached for comment.