POLITICAL CASES?
The government rejects accusations that NAB is impacting the economy, calling such allegations opposition propaganda, and says graft is to blame for Pakistan's current economic woes.
Khan last month launched a commission to investigate projects and agreements that helped increase overall debt between 2008-2018, staffing it with members of NAB and military intelligence agencies.
Science Minister Fawad Chaudhry said government officials make up a small number of NAB cases, but their concerns had reached Khan and a special cell had been created within NAB to deal with bureaucrats' issues.
"The rise of Imran Khan is basically a middle class revolution against corruption," Chaudhry added. "You can't expect from us that we will take the issue of corruption lightly."
NAB last month arrested former President Zardari and his sister over alleged false bank accounts and money laundering. They both deny wrongdoing and call the arrests politically motivated.
Since Khan assumed power last August, NAB has continued investigating jailed former Prime Minister Sharif, who has alleged the military's hidden hand is behind many of the anti-corruption cases against his family.
Fresh probes have also been opened involving Sharif's brother and many of his closest allies, including at least eight ministers from the previous government. They all deny wrongdoing and say they are victims of persecution.
"Everybody who is against this government has a NAB case," said one opposition politician who was a minister in the previous government.
Inquiries have also been launched against some prominent businessmen.
"KILLS CONFIDENCE"
Pakistan's new liquefied natural gas (LNG) infrastructure, erected at breakneck speed by the previous administration, has emerged as a major anti-corruption battlefield.
LNG terminals built in 2016 and 2017 were vital to ending a decade of electricity shortages and turned Pakistan into one the world's hottest LNG markets, with Qatar and Italy's Eni signing long-term gas deals worth billions.
But Khan's Pakistan Tehreek-i-Insaf (PTI) party has for years alleged corruption. In April, on NAB's instructions, the government barred former Prime Minister Shahid Khaqan Abbasi, ex-Finance Minister Miftah Ismail, and six bureaucrats involved in the Qatar deal for the first terminal from leaving the country. They all deny wrongdoing. No allegations of wrongdoing have been made against the Qatari side.
Abbasi, who as petroleum minister masterminded Pakistan's embrace of LNG, said he had to take a lead role because many officials were afraid of multi-billion dollar projects.
"Nobody wanted to do anything as they were scared of NAB," said Abbasi, who said bureaucrats were now paying a price despite helping end electricity shortages. "We had good people who stuck their neck out and they're all suffering today."
A third LNG terminal and a new gas pipeline needed to keep up with rising energy demand have been on the "backburner" for more than a year as no decision making is taking place across ministries, according to an energy official.
"Bureaucrats being barred from leaving the country kills confidence," he said. "We are going to have a (energy) crisis in a year or two."
The result, say the officials who spoke to Reuters, is that senior colleagues nearing retirement are refusing to sign off on projects due to fears of being dragged out of retirement to answer NAB inquiries for years.
"If I have to make a decision about a $10 billion refinery... I'll sit on this file for six months, and get the next guy to make that decision," said the first senior federal official.
A senior civil servant in the Khyber Pakhtunkhwa province said he hasn't approved any major project since late 2018.
"All bureaucrats know that once you are tagged with NAB, no matter if you're innocent or you really did some corruption, you have no future," he said. "You're finished."