A massive leak of 11.5 million tax documents has reportedly exposed the secret offshore dealings of around 140 political figures globally.
The vast stash of records, covering around 40 years, was obtained from an anonymous source by German daily Sueddeutsche Zeitung and shared with media worldwide by the International Consortium of Investigative Journalists (ICIJ).
According to the documents, three of Sharif's four children -- Maryam, Hasan and Hussain -- "were owners or had the right to authorise transactions for several companies".
"Nawaz Sharif should explain how his children made all this money," Imran said.
Also Read
Amid the furor, Sharif's son Hussain Nawaz said he had already stated that he owned the offshore companies and he owned many apartments under them.
He said Nawaz Sharif's name was being used wrongly and all accusations being levelled against him were baseless.
"I have already said that my sister Maryam is a trustee of our offshore companies. Her name has been included as a trustee like various other people," he was quoted as saying by the News. He argued that a trustee is not the owner.
Meanwhile, Pakistan's Information Minister Pervaiz Rashid said that Panama Papers had vindicated his government's stand that Prime Minister Sharif and his brother Shahbaz Sharif do not own any business abroad.
The Sharif brothers have not been mentioned but Maryam, tipped to be the Premier's who political successor, along with her two brothers has been mentioned in the papers.
"Panama documents show what we have been saying that Prime Minister Nawaz Sharif or (his brother) Shahbaz Sharif do not have any property or business in any other country," Rashid said.
"They are like many other Pakistanis who live abroad and do business," Rashid said.
(Reopens FGN 21)
Hussain said it is a common perception that they took loans from banks.
"That means we deal in businesses of lakhs of rupees. There are many others who are running businesses in others' names, but we fully follow all rules and regulations in doing any business," Hussain said.
Launching an attack on the Sharifs, Imran said, Probes have already been initiated in several countries -- including Australia, New Zealand, Sweden and France -- across the globe after their leaders and office bearers were implicated."
He went on to say that "Nawaz Sharif should explain how his children made all this money."
How can those who launder money from Pakistan to offshore accounts ask others to invest in Pakistan?" he said.