Dr Abdul Wahid Soomro (MNA Pakistan Peoples Party)

A British woman who was murdered in Pakistan was shot more than 100 times, an MP told parliament yesterday.

Tania Yousaf, 22, of Nelson, Lancashire, was killed on 20 May with her parents, Mohammed and Pervez Yousaf, at a graveyard near Gujrat in the Punjab region.

The family's MP, Andrew Stephenson, who represents the Pendle constituency, told parliament the investigation "appeared to be going nowhere", blaming alleged corruption and the complexities of the Pakistani legal system.

Relatives of the victims are campaigning to keep the case in the public eye and travelled to London for the adjournment debate.

Foreign and Commonwealth Office officials have been asked to raise awareness of the high number of violent attacks recently on British nationals in Pakistan.

Stephenson said Qamar Abbas and Sheraz and Naveed Arif – who are both related to the Yousaf family – had "unbelievably" been granted bail after being accused of the murders.

He described the attack, which took place during a family visit to Pakistan for a wedding.

"After dragging Tania from the car, they [the attackers] made her call her husband for help on her mobile phone," he said.

"The call connected but before Tania could explain to her husband what was happening, she was killed – with him still listening on the line.

"To further illustrate the sheer brutality of these murders, I can for the first time, with the permission of the Yousaf family, reveal that, at Tania's postmortem, more than 100 bullets were recovered from her body."

Stephenson, a Conservative, said the apparent failure of the investigation could have a wider community impact.

"British Pakistanis will simply not visit or invest their money in Pakistan if the law and order situation continues to deteriorate and the judicial process seems incapable of delivering justice", he said.

Sheraz and Naveed Arif are the brothers of a woman who had been married to Kamar Yousaf, the eldest son of the Yousafs. Their marital difficulties are thought to have led to the murder.

The Foreign Office minister, Alistair Burt, said the murders had "not been an isolated incident".

Nine British citizens, in addition to the Yousafs, had been murdered in Pakistan since October 2009, he said.

Burt, the minister responsible for South Asia, said he would raise his concerns with the Pakistan high commissioner.