PML-N leaders claimed that around 300 workers were arrested from Rawalpindi on Tuesday, while several hundred others had been picked up from Lahore and other cities.
Nawaz Sharif and Maryam Nawaz arrived in London prior to Eid-ul-Fitr and are now there due to Kulsoom Nawaz's prolonged illness.
Earlier, the ousted prime minister had released a video message ahead of his arrival in Pakistan, asking people to support him in his struggle which he said he is waging for the future of coming generations.
NAB arranged two helicopters expected to take the father and daughter duo to Adiala jail.
Nawaz Sharif was also fined eight million and Maryam Nawaz two million pounds.
Sharif returned from Britain after an anti-corruption court handed him a 10-year jail term and sentenced his daughter and political heir to seven years in prison for failing to prove that money used to buy luxury flats in London in the 1990s was not ill-gotten.
"I'm aware of the fact that I'll be jailed, but it's a very small price to pay for the great mission to save the sanctity of the vote in Pakistan", Sharif told Reuters on board the plane minutes before touching down in the central city of Lahore.
Adding to the tension surrounding the upcoming poll, a suicide bomber hit an election rally of a regional party in southwestern Pakistan, killing 85 people. A second stint in power was ended by a military coup in 1999, prompting a period in jail for Sharif and years in exile in London.
The picture shows Maryam breaking down into tears and Nawaz keeping his hands on Kulsoom's head.
Sharif's return comes at a time of dwindling fortunes for his party, which one year ago was considered a run-away favourite to retain power.
After the Supreme Court ousted Sharif as prime minister last July, the courts barred him from heading the party he founded.
The armed forces, which have directly ruled Pakistan for nearly half of its existence, have repeatedly denied interfering in the election.
Further, the PML-N president said the verdict in the Avenfield reference was "unjust".
PML-N has also been riven by internal divisions.
The defiant leader questioned the credibility of the July 25 polls amid a crackdown on his supporters.
"Those who think they can scare us.open your ears and hear this: we are winning this election", Shehbaz Sharif told reporters in Lahore on Thursday.