Chief Justice Gulzar Ahmed (L) administers the oath to justice Ayesha Malik in Islamabad on Monday. AFP

Malik attended a ceremony in the capital Islamabad where she now sits on the bench alongside 16 male colleagues at Pakistan's highest court.

"I want to congratulate Justice Ayesha Malik on becoming the first woman judge of the Supreme Court," Prime Minister Imran Khan said. "I wish her all the best," he added on Twitter.

Lawyer and women's rights activist Nighat Dad said Malik's promotion is "a huge step forward." "It is history in the making for Pakistan's judiciary," she said.

Malik was educated at Harvard University and served as a high court judge in Pakistan's eastern city of Lahore for the past two decades.
She has been credited with rolling back patriarchal legal mores in her Punjab province jurisdiction.

Last year she outlawed a deeply invasive and medically discredited examination used to determine a woman's level of sexual experience.

Women in Pakistan often struggle to gain justice in rape and sexual assault cases, and the test was deployed as a means of discrediting victims by casting aspersion on their character.

Malik's elevation to the apex court of Pakistan may clear the way for more women to enter the historically conservative and male-dominated judiciary of the Islamic republic.

"She has broken all barriers in the judicial system and it will allow other women in the system to move forward," said lawyer and women's rights activist Khadija Siddiqi. "I hope this will lead to more women-centric decisions by the judiciary in the future."

But her appointment has been mired in controversy for the past four months, with claims she jumped a queue of more senior male candidates qualified for the post. Earlier this month the Pakistan Bar Council staged a strike to protest against Malik's nomination.

Agence France-Presse