Qayyum said he would probably be banned because he had been sentenced to life imprisonment before he went into exile in 2000.
Sharif was exiled a year after he was overthrown by General Pervez Musharraf, Pakistan's president, in a bloodless coup.
His charges relate to corruption cases and also to his alleged attempt in October 1999 to block a plane carrying Musharraf, his army chief at the time, from landing in Pakistan.
That action prompted Musharraf to topple Sharif.
Sharif had also been disqualified from standing in the elections by the country's anti-corruption body.
Thousands of supporters chanting "Long live Sharif!" had gathered on Sunday to greet Sharif back into the country.
Accompanied by his brother Shabaz, Sharif smiled and waved to the crowd as he entered Allama Iqbal international airport's arrivals lounge in Lahore.
Sharif originally tried to return home in September, but was sent back to Saudi Arabia within hours of touching down.
However this time, Musharraf, who imposed emergency rule on November 3, is expected to let Sharif stay.'Best moment'
"I am very happy to be back ... it is the best moment of my life," senior party aides quoted Sharif as saying as he arrived on an aeroplane provided by King Abdullah of Saudi Arabia.
"My return is not the result of any deal," he told reporters. "My life and death are for Pakistan.
"We will fully participate in national politics. We don't believe in the politics of vengeance."
Al Jazeera's Kamal Hyder in Lahore said there were noisy scenes outside the terminal.
"Everybody has been waiting for this day for some time," he said. "No one has been able to get close to Nawaz Sharif because of the crowds."
About 1,000 of Sharif's supporters found a way through tight security to enter the terminal building, waving the green flag of his party and shouting "Prime Minister Nawaz Sharif" and "Go, Musharraf, go!"
Workers decorated the streets with banners, posters and portraits, while crowds lined the route from the airport to the city. Loudspeakers on cars blared out music and people waved victory signs.
Yasin Butt, one of Sharif's supporters, said: "The lion is returning, and when the lion roars, dictators and political turncoats disappear."
Sharif's party said about 1,800 of its supporters had been detained in a crackdown on Saturday night in the eastern Punjab province, of which Lahore is the capital.
But Nisar Memon, the federal information minister, said the figure was an exaggeration.
"There are no arrests as such," Memon said. "About 100 people have been confined so that they do not create any issues. We don't want the same mess as there was in Karachi."
When Bhutto returned to Pakistan huge crowds gathered for a street procession welcoming her through Karachi. Bombers attempted to assassinate Bhutto on the route, killing nearly 140 people.
Pakistan's political opposition is split over whether to boycott upcoming general elections.
Sharif indicated on Sunday that his party would demand a restoration of constitutional rule before it took part in the vote, but that any decision on whether to boycott would be taken in conjunction with other groups.
"These [emergency] conditions are not conducive to free and fair elections," he said. "I think the constitution of Pakistan should be restored, and there should be rule of law."
Raja Pervez Ashraf, secretary-general of Bhutto's PPP party, welcomed Sharif's return and said it would help establish an open political atmosphere.
|Bhutto filed her nomination for the election a day before the Monday deadline [AFP]|
"There is already an understanding on one point, the restoration of democracy in this country," he said.
"We honestly feel that Pakistan needs democracy and a free and fair election is the only way out."
Sharif's return could further complicate the situation for Musharraf, who imposed a state of emergency three weeks ago saying that it was needed to tackle an increase in violent attacks.
But the president's opponents say that most of those targeted have been political opponents, lawyers and members of the media.
Source: Al Jazeera and agencies