Mother-of-two Mumtaz Sattar died in the country's Punjab province last month.
Her husband, Abdul Sattar, 40, has been arrested by police investigating her death along with three other men, according to a lawyer acting for the family.
Solicitor Aamer Anwar said Mr Sattar was being held in custody at Nankana District Police Office.
The couple, who had been married for 14 years and have two daughters aged 10 and 13, were on a trip to Pakistan to visit Mr Sattar's family at the time.
Mr Sattar, who ran a newsagents in Port Glasgow, told police they were drugged, attacked and robbed by two men during a taxi ride on September 21.
He said they were thrown out of a moving car and his wife died from head injuries. She was buried days later.
However, her family say that they do not believe his version of events.
Backed by their legal team, as well as Humza Yousaf, MSP, and Governor of the Punjab region and former Glasgow MP Mohammad Sarwar, they are calling for justice.
First Minister Alex Salmond and officers from Police Scotland are also said to have assisted the family.
Their lawyer, Mr Anwar, said that without such help Mrs Sattar would have been "another woman brutally murdered in the heart of the Punjab that no-one there cared about".
At a press conference yesterday Mrs Sattar's sister Mehnaz Jilani, 29, from Glasgow, broke down as she spoke of the impact on her family.
Accompanied by her two sisters and brother, she said: "These past three weeks have been full of shock and disbelief for the whole family.
"We do know that we have a long way to go yet but the initial version of the event just did not add up, hence all the help that was drafted in to bring out the truth.
"Our sister would always take care of us all and keep us right. Our sister never deserved this horrific attack and all behind it should be given the upmost sentence there is."
She spoke of how she would miss her sister.
She said: "A big part of our family life is now gone. No more visiting each other. No more phoning each other. No texting each other. No more going out. No more big sister.
"All we are asking for is justice."
Mr Sattar and the other three men arrested are expected to spend 14 days in custody before formal charges are brought, said Mr Anwar.
He told the press conference: "I can advise that Abdul Sattar has now been formally arrested and is presently in custody at Nankana district police office.
"Three other suspects have also been formally arrested. These men who were on the run following the recovery of a white car on Sunday are allegedly linked to the white car and to Abdul Sattar.
"Critical to the investigation has been the recovery of the white car which Mr Sattar claimed was a taxi and used to transport him and Mumtaz from outside the security perimeter of the airport in Lahore.
"Police have confirmed this car is not a taxi and that Mr Sattar was seen on CCTV footage from the airport greeting the males from the car."