A team of civilian and military investigators found there was a "significant disparity" between the Sharif family's income and lifestyle in its report submitted to the court earlier this month.
Pakistan's Supreme Court was set to announce a new judgement on Friday that could topple Prime Minister Nawaz Sharif who is embroiled in a long-running corruption case that has gripped the country.
Around 3,000 police and paramilitary forces were to be deployed around the court in Islamabad ahead of the ruling, due to be announced Friday morning, a police spokesman said.
The court had in April declared there was "insufficient evidence" to oust Sharif over the graft allegations engulfing his family, and ordered an investigation team to probe the matter.
The team of civilian and military investigators found there was a "significant disparity" between the Sharif family's income and lifestyle in its report submitted to the court earlier this month.
TRT World's Nafisa Latic has more details.
Sharifs reject claims
The Sharifs and their allies have consistently and noisily rejected the claims, with his ruling PML-N party this month dismissing the investigation team's report as "trash."
Analysts were divided on what the court might do, though Michael Kugelman of the Woodrow Wilson Institute in Washington noted there was a "pretty strong precedent of the Pakistani judiciary being very active and essentially sending elected officials packing."
However, he added, the case has been "more about his family" than Sharif himself. "You have to acknowledge the fact that Nawaz Sharif himself is not really being accused of anything that is against the law."
The controversy erupted last year with the publication of 11.5 million secret documents from Panamanian law firm Mossack Fonseca documenting the offshore dealings of many of the world's rich and powerful.
Three of Sharif's four children — Maryam, his presumptive political heir, and his sons Hasan and Hussein — were implicated in the papers.
At the heart of the case is the legitimacy of the funds used by the Sharif family to purchase several high-end London properties via offshore companies.
The PML-N insists the wealth was acquired legally, through Sharif family businesses in Pakistan and the Gulf.
The push against Sharif has been spearheaded by cricketer-turned-politician Imran Khan and his Pakistan Tehreek-e-Insaf party, who said Sharif has lost "moral authority."
Bribery and other forms of graft are endemic in Pakistan, with the country coming in 116th place out of 176 countries ranked according to corruption by Transparency International in 2017.
Sharif has been ousted by graft allegations once before, during the first of his three terms as prime minister in 1993.
He has not yet completed a term as prime minister, having been toppled in his second term by a military coup in 1999.
The allegations are a blow to his credibility ahead of general elections due to be held by next year, and as the civilian government appears to have reached an uneasy detente with the military, which has ruled Pakistan for half of its existence.
His party currently has no clear successor in place. Daughter Maryam does not hold public office, while his brother Shahbaz Sharif, the current chief minister of Punjab province, holds only a provincial seat.