Relatives of Saif Rehman say they have still not received any positive developments over the extradition of the chief suspect from the US to Pakistan, nearly a year after he died.
And for the first time they have raised concerns that Pakistani authorities may not be taking the case seriously enough for cultural reasons.
Mr Rehman, 31, who lived in Ibrox, Glasgow, for six years, and his American wife Uzma Naurin, 30, were shot dead when their car was ambushed on November 1 last year in Lalamusa in the Punjab province of Pakistan.
Ms Naurin, who lived in New York, was the first woman in her family to shun the traditional arranged marriage and wed someone outside of the family.
It is said her parents could not accept it and she moved out of the family home.
Mr Rehman's brother, Abdul Majid, appealed for urgency in bringing his brother's killer to justice. He said the family had heard there are no moves to extradite the chief suspect, Ms Naurin's father, Muzafar Hussain, who lives in New Jersey in the US.
Mr Majid said: "We tried to get justice but nobody is interested, not even the police or the courts and who knows what is going on. It is very difficult to find justice in Pakistan.
"Honour killings are not accepted by law. You can see in the whole world, if you hurt someone, you punch somebody, it is against the law and you have to be punished. Whatever culture it is you should get punishment.
"I still hope that we will get justice."
He said he believed the family would have to pay the police to get justice but could not afford it. "We cannot pay to the lawyer and cannot pay to the police. We can't," he said.
Amnesty International has previously raised concerns that gender-based violence, including rape, forced marriages, so-called honour killings, acid attacks and other domestic violence are being committed with impunity in Pakistan as police are reluctant to register and investigate complaints.
The Human Rights Commission of Pakistan recorded 791 honour killings of women last year, with at least 26 of them raped or gang raped before being murdered.
In the Gujrat district of Punjab, where the killings of Mr Rehman and his wife took place, more than 40 women were murdered in a four-month period this year. Most of those killed were accused of dishonouring their families. However, human rights activists fear many more killings go unreported, and the perpetrators, often close family members, go unpunished.
Some experts have previously said they believe any extradition to Pakistan would not be straightforward because the treaty between the US and Pakistan was signed in 1931 when the UK controlled the territory.
While the accord is believed to be valid, it is claimed lawyers could delay matters for at least a year by questioning it.
Soon after the murders, Mr Rehman's Pakistani parents Mohammad and Gulnisa Zakir wrote to the US ambassador in Pakistan, Cameron Munter, asking for help in tracing those responsible.
But the US Embassy in Islamabad refuses to discuss the case, passing all inquiries to the Pakistani authorities. Local and regional police have persistently failed to respond to requests for information from The Herald about the progress of the case over many months.
The couple were gunned down while in Pakistan for the wedding of one of Mr Rehman's brothers.
Mr Rehman and his wife had planned after the wedding to settle down to a new life in the US, having had a long-distance marriage over the previous three years. Mr Rehman, a Pakistani citizen, ran a mobile phone repair centre, and Ms Naurin, worked at a Costa Coffee outlet in New York.
Mr Rehman was shot dead in front of his sister, Fauzia, and two-year-old niece in Lalamusa.
It is understood Ms Naurin had been married previously, but her first husband took his own life.
Ms Naurin subsequently refused to enter an arranged second marriage with her late first husband's brother because he was too young.
Mr Rehman and Ms Naurin were married in a private ceremony in Glasgow with just three witnesses three years ago.
They held a walima (marriage banquet) at the Kabana Restaurant in Kinning Park in June last year in the hope Mr Hussain, who had flown to Scotland from the US, might come round to the idea of the wedding.
On the day of the killing, Mr Hussain discharged himself from the army-run CMH Kharian Cantonment hospital in Gujrat where he was having a minor operation.
The family say he never went to the funeral and police say he drove to the port city of Karachi in a rental car and boarded a flight for the US.
Mr Hussain has denied involvement in the deaths.
Contextual targeting label: