The National Accountability Bureau's (NAB) Rawalpindi office on Sunday sent a notice to PPP Chairman Bilawal Bhutto-Zardari and co-chairman Asif Ali Zardari, asking the father-son duo to appear before the bureau on December 13.

According to NAB spokesperson Nawazish Ali Asim, the notice has been sent in pursuance of a case regarding Park Lane Estates (Pvt) Limited, a Karachi-based real estate firm.

PPP leader Farhatullah Babar told DawnNewsTV that Bilawal's name is among the shareholders of the company.

The PPP leader said that the party chief has begun consultations with his legal team upon receiving the notice.

"A team of Chairman Bilawal Bhutto's lawyers will appear before NAB Rawalpindi on Dec 13," said Bilawal's spokesman, Senator Mustafa Nawaz Khokhar, in a statement issued later.

It wasn't immediately clear if Zardari plans on appearing before NAB or he too will send a legal team.

Terming the notice sent to the PPP chairman as "ludicrous", Senator Khokhar said: "Bilawal Bhutto is being questioned regarding matters from a time period when he was merely a year old."

"These are simply tactics employed by NAB for political revenge and to instil fear in the opposition," the spokesman alleged.

Pointing the finger at Imran Khan, the PPP leader alleged that the "selected prime minister" wants the playing field to be left empty for him whereas he should have the courage to face criticism and opposition "now that he is in power".

According to a report by The Express Tribune, the executive board of NAB on May 23 had approved an investigation against Capital Development Authority officials for allegedly allotting land belonging to Punjab Forest Department to Park Lane Estates (Pvt) Limited.

The firm was previously owned by Zardari, Bilawal and a few others, the publication reported.

Zardari will be questioned by NAB regarding his source of income when he established the company and Bilawal will be asked to provide details of funds used to obtain shares in the company, the bureau's spokesperson revealed.

Bilawal was previously served two notices by a Joint Investigation Team (JIT) formed by the Supreme Court to probe alleged laundering of billions of rupees through fake bank accounts in connivance with bankers and others to several suspected beneficiaries, including former president Zardari and his sister Faryal Talpur.

The JIT had sought Bilawal's bank account details for which questionnaires had been sent to him.