Islamabad, Aug 22 - Pakistan is estimated to have lost a staggering Rs.150 billion ($1.8 billion) thanks to the immunity granted to politicians, bureaucrats and senior military officers charged with corruption and the scrapping of the country's corruption watchdog, a media report said Saturday.

While Rs.100 billion was lost due to the National Reconciliation Ordinance (NRO) then president Pervez Musharraf promulgated in 2007, another Rs.50 billion will be lost with the winding up of the National Accountability Bureau (NAB) that was investigating corruption cases against the high and the mighty.

'While the nation is still mourning the loss of Rs.100 billion as a result of the infamous NRO, many more billions are about to be lost, as the dying NAB has been rendered useless to pursue ripe cases of corruption,' The News said.

It quoted sources in the NAB as saying that 'after being made a dormant organisation for the last two years, the bureau is no more effectively pursuing certain high-profile cases of corruption involving at least Rs 50 billion'.

The sources said the NAB, 'which is on the verge of its death, has dozens of ripe cases of mega corruption while it is also receiving complaints of massive corruption in government departments, but it remains unmoved'.

The NRO had enabled former prime minister Benazir Bhutto and a host of other politicians to return from exile by granting them immunity from the corruption charges pending against them in various Pakistani courts.

In April, a bill to scrap the NAB and transfer its powers to the legislature was tabled in the National Assembly, the lower house of parliament.