The National Accountability Bureau (NAB) on Saturday filed an appeal against Asif Ali Zardari's acquittal in a corruption reference that accused the PPP co-chairman of acquiring assets through illegal means.

The appeal was filed at the Lahore High Court's Rawalpindi bench by NAB officials.

The plaintiffs in their appeal have demanded that the Rawalpindi accountability court's judgement acquitting Zardari in the assets reference be discarded and the case be referred to a trial court.

The appeal, a copy of which is available with DawnNews, states that NAB has a "tremendous amount of documentary evidence relating to the properties and bank accounts and other movable and immovable assets" which could have been used to take the investigation further.

A NAB spokesperson told DawnNews that the accountability court issued acquittal orders of Zardari without taking into consideration the "solid evidence" submitted by NAB.

"The court has acquitted Zardari as a result of a hasty trial which will set the wrong precedent [for future cases]," he said.

The request for Zardari's acquittal, submitted by his counsel and PPP leader Farooq H. Naek, was accepted by Justice Khalid Mahmood Ranjha, who ruled that the reference lacked a legal basis.

Zardari had previously been exempted from appearing in the case owing to security concerns.

The reference against Zardari was filed before an accountability court in 2001, but was closed in 2007 under the National Reconciliation Ordinance (NRO) issued by the government of retired Gen Pervez Musharraf.

The Supreme Court, in its verdict in the NRO case on December 2009, had ordered the revival of all cases closed under the ordinance. By then, however, Zardari had been sworn in as president and therefore, enjoyed immunity under Article 248 of the Constitution.

Zardari has faced a total of six corruption references; apart from the assets reference, the former president was also implicated in the SGS, Cotecna, Polo Ground, Ursus Tractors and ARY Gold corruption references.

NAB reopened these references once Zardari had completed his term office, but the former president had already been acquitted in five of the six references after a retrial before the accountability court.