Mr Sharif, 67, left for Saudi Arabia on a Saudi Airlines flight on December 30. His younger brother and Punjab Chief Minister Shahbaz Sharif was already in Saudi Arabia on an "official visit".
It was reported that Shahbaz had gone there to prepare the ground for the visit of his brother who opposition parties claimed needed his friends in the Saudi royal family to reach a "deal" with Pakistan's military to get a relief from the graft cases linked to the Panama Papers scandal.
"Nawaz Sharif and Shahbaz Sharif met Crown Prince Mohammad bin Salman in Jeddah during their stay. However their meeting had nothing to do with any kind of deal here in Pakistan," said Senator Pervaiz Rashid, a close aide of Sharif.
He said the details of the visit to will become known in the coming days.
Both brothers had a meeting with the Crown Prince during their stay. Nawaz Sharif stayed for three days while Shahbaz for a week in Saudi Arabia.
Shahbaz told reporters on his return yesterday that their visits to Saudi were not of "unusual" nature.
"Our visit to Saudi Arabia was not unusual. I will hold a separate press conference to discuss the visit," he said.
Asked if the visit had anything to do with the attempts to get another National Reconciliation Ordinance (NRO) for the Sharif family to get relief from corruption cases, he said, "For God's sake. Saudi Arabia is one of the best friends of Pakistan. It has always helped Pakistan during crises like floods, earthquakes and wars".
Opposition leaders Imran Khan and Asif Ali Zardari have consistently held that the only reason the Sharif brothers had visited Saudi Arabia was to talk about a possible "deal" with the establishment.
Punjab government spokesman Malik Ahmad said Chief Minister Shahbaz had met Prince Mohammad to discuss Saudi Arabia's absence from the summit on Al-Quds in Turkey last month, and insisted that his meeting should only be seen in this context.
Earlier, Foreign Minister Khawaja Asif rejected the opposition's charges, arguing that the Sharifs had spent eight long years in exile in Saudi Arabia and enjoyed good relations with the royal family.
Saudi Arabia had brokered a deal with former army chief General Pervez Musharraf in 2000 to provide safe passage to the Sharif family to live in exile in the kingdom after Musharraf had toppled Nawaz Sharif's government in 199.
Nawaz Sharif had to step down as chief of the Pakistan Muslim League-Nawaz (PML-N) after he was disqualified as prime minister by the Supreme Court on July 28 in the Panama Papers scandal.
The Sharif family is facing three corruption cases linked to the scandal.
The political future of Mr Sharif, who leads the country's most powerful political family and his party, has been hanging in the balance since then. If convicted, he can be jailed.
Nawaz Sharif's family alleges that the cases are politically motivated.