The Pakistani intelligence service has made a rare public statement denying any involvement in the murder of journalist Saleem Shahzad.
The 40-year-old vanished at the weekend after leaving home in Islamabad. His body was found on Tuesday.
The intelligence service said that any suggestion that it had a role in his murder was "baseless... and unfounded".
But a senior newspaper executive insisted that Mr Shahzad received death threats on at least three occasions.
Hameed Haroon, the chief executive of the Dawn Group of Newspapers, said in a statement released on Thursday that the dead journalist told him that he had received "death threats from various officers of the Inter-Services Intelligence (ISI) on at least three occasions in the past five years".
Mr Shahzad made a career writing about various Islamist militant networks operating in Pakistan and had recently written an article about article about al-Qaeda infiltration in Pakistan's navy.
But in what correspondents say is an unusual move, an ISI official said on Wednesday that the incident "should not be used to target and malign the country's security agency".
"Baseless accusations against the country's sensitive agencies for their alleged involvement in Shahzad's murder are totally unfounded. In the absence of any evidence and when an investigation is still pending, such allegations are tantamount to unprofessional conduct on the part of the media," the official told the Associated Press of Pakistan.
"The ISI offers its deepest and heartfelt condolence to the bereaved family, and assures them that it will leave no stone unturned in helping to bring the perpetrators of this heinous crime to justice."
In a warning to the Pakistani media, the official said that it "should refrain from [making] baseless allegations against the ISI that seek to deliberately malign the organisation in the eyes of the people of Pakistan".
But Mr Haroon said that Mr Shahzad's purpose "was not to defame the ISI but to avert a possible fulfilment of what he clearly perceived to be a death threat".
"The last threat which I refer to was recorded by Mr Shahzad by e-mail with me, tersely phrased as 'for the record' at precisely 4.11 am on 18 October 2010, wherein he recounted details of his meetings at the ISI headquarters".
Pakistan has ordered an immediate inquiry into his kidnapping and murder.
The BBC's Syed Shoaib Hasan - who attended Mr Shahzad's funeral on Wednesday in Karachi - said there has been no comment from the government over the circumstances of Mr Shahzad's murder, except for a statement from Prime Minister Yousuf Raza Gilani immediately after the body was discovered on Tuesday.
Mr Gilani said that the culprits would be brought to justice "at every cost".
Mr Shahzad's body was found about 150km (90 miles) south-east of Islamabad. Police said it bore marks of torture.
A post mortem report said that there were "15 torture marks" on his body, and no bullet wounds.
It said the death was probably caused by a fatal blow to the body in the chest region.
US Secretary of State Hillary Clinton said that Washington "strongly condemned the abduction and killing" of Mr Shahzad.
"His work reporting on terrorism and intelligence issues in Pakistan brought to light the troubles extremism poses to Pakistan's stability," she said in a statement.
Mr Shahzad worked for the Italian news agency Adnkronos International (AKI) and was Pakistan bureau chief for Asia Times Online.
Human rights groups recently called Pakistan the most dangerous place in the world for journalists to operate, saying they were under threat, not only from Islamist militants but also Pakistan's military and intelligence agencies.