A team of the National Accountability Bureau (NAB) took former army captain Muhammad Safdar into custody minutes after his arrival from London at the Benazir Bhutto International Airport along with his wife Maryam Nawaz.
Safdar has been nominated by NAB in one of three corruption cases filed on September 8 against Pakistan's former premier Sharif, his daughter Maraym, sons Husain and Hasan and his son-in-law Safdar.
The couple had arrived to appear before an anti-graft tribunal in connection with the NAB reference pertaining to London properties owned by the Sharif family.
Safdar was later presented before a court in Islamabad, NAB officials said. Maryam, who was not detained, separately appeared in the same court for the first time.
However, Sharif and his two sons were absent as they are in London where 67-year-old Sharif's wife is battling throat cancer.
Sharif attended the previous two hearings but went to London last week to see his ailing wife.
The court held brief hearing and took a break before announcing the hearing will resume shortly. During the brief hearing, Maryam was given copies of the case documents.
Sharif's lawyer also presented an application to exempt him from appearance today as he was with his wife in London.
The trial judge had earlier issued non-bailable warrants for the arrest of Safdar and Sharif's two sons for failing to appear in court in the last hearing held on October 2.
The court, however, repeated the bailable warrants for Sharif's daughter.
"We are going back and will appear before the court and go through the wheels of justice. We respect the rule of law and the Constitution," local media quoted Maryam as saying.
Asked whether her brothers would return to Pakistan to face the NAB references against them, she said, "Hassan and Hussain would themselves tell you about their decision".
Safdar told Geo News that the couple had decided to return to Pakistan on the advice of their lawyers.
Sharif had to step down as prime minister and president of the ruling PML-N party after he was disqualified by the Supreme Court on July 28 in the Panama Papers scandal.
Sharif was re-elected as the president of the ruling PML-N on October 3 and immediately demanded that those who disqualified him should respect the people's mandate and democracy.