Honor killing
Members of civil society and the Human Rights Commission of Pakistan hold placards during a protest in Islamabad May 29, 2014 against the killing of Farzana Iqbal, 25, by family members on Tuesday in Lahore. Reuters/Faisal Mahmood

The husband of Farzana Iqbal, the pregnant Pakistani woman who was stoned to death Tuesday in a so-called “honor killing” by her family, killed his first wife so he could marry Iqbal, according to CNN.

Iqbal’s husband, Mohammad Iqbal, reportedly said on Thursday that he had strangled his first wife to death and was later arrested. According to reports, the incident happened six years ago and Mohammad was released on bail after his son forgave him. Zulfiqar Hameed, a senior police officer investigating the killing of Iqbal, reportedly said that police will file a report with details of Mohammad’s past crime and described him as a “notorious character.”

"I wanted to send a proposal to Farzana, so I killed my wife," Mohammad told CNN in an interview Thursday. His son, Aurengzeb, confirmed his father’s statements to CNN and said that his father had served a year in jail.

Iqbal, who was three months pregnant, was attacked while she was waiting outside Lahore High Court in Pakistan to contest an abduction case her family had filed against her husband. The woman’s family, including her father, two brothers and her former fiancé attacked her with stones and bricks in broad daylight, before a group of men joined the attack.

Pakistani Prime Minister Nawaz Sharif called for “immediate action” over the death of the woman and has demanded an explanation from the police about their inaction during the attack on Iqbal.

"I begged them to help us but they said, this is not our duty," the 45-year-old Mohammad told Reuters.

A statement from Sharif's office reportedly described Iqbal's death as a "brutal killing" and said it was "totally unacceptable.”

“I am directing the chief minister to take immediate action,” Sharif reportedly said in the statement.