Islamabad has asked authorities in Tehran to assist in the arrest of the suspects behind the assassination of Saudi diplomat Hassan al-Qahtani in Pakistan's Karachi in 2011.
Reports have said the killers had fled to Iran.
The Kingdom's ambassador to Pakistan, Nawaf al-Malki, told Asharq Al-Awsat that Saudi Arabia was informed by Pakistan that the murderers were indeed in Iran.
Saudi authorities are dedicating all of their efforts to cooperate with Pakistan to arrest them and allow justice to take its course, he added.
A Saudi committee has been formed to tackle the case and it flew to Islamabad two months ago.
New leads in the case had emerged, prompting Pakistan in November to request Iran's assistance to locate the suspects, who have been identified as Ali Mustehsan, Raza Imam and Syed Waqar Ahmed
Qahtani was a diplomat at the Saudi consulate in Karachi.
He was killed after gunmen riding on two motorbikes opened fire at him in his car as he was headed to work.
