Iran having trust issues with Hezbollah after Hassan Nasrallah’s killing?

Iran’s supreme leader, Ayatollah Ali Khamenei, had reportedly sent Iranian Revolutionary Guards commander, Brigadier General Abbas Nilforoushan, to warn Hezbollah leader Sayyed Hassan Nasrallah to flee Lebanon. Sources told Reuters that Nilforoushan was with Nasrallah in his bunker when Israeli bombs hit it, and he was also killed in the attack. 
Nasrallah was killed days after thousands of pagers and walkie-talkies used by Hezbollah exploded in deadly attacks on Sept 17 and 18. The incident has further escalated the conflict between Israel and Iran-backed Hezbollah, raising fears of an all-out war in West Asia. 
Sources told Reuters that Iran’s Khamenei is now deeply worried about Israeli infiltration of senior government ranks in Tehran.
Immediately after the attack on Hezbollah’s pagers on September 17, Khamenei had reportedly cited intelligence reports that suggested Israel had operatives within Hezbollah and was planning to kill Nasrallah, one of the sources, a senior Iranian official, said.
The assassination of Nasrallah, Iran’s fears for the safety of Khamenei, and the loss of trust between Tehran and Hezbollah, as well as within Hezbollah, were reflected in conversations with 10 sources Reuters spoke with.
Meanwhile, four Lebanese sources said that the recent killing of key Hezbollah leaders is making it hard for the Iran-backed militant group to choose a new leader, fearing the “ongoing infiltration will put the successor at risk.”
Magnus Ranstorp, a Hezbollah expert at the Swedish Defense University, was quoted as saying, “Basically, Iran lost the biggest investment it had for the past decades…It shook Iran to the core. It shows how Iran is deeply infiltrated also: they not only killed Nasrallah, they killed Nilforoushan.”
An Iranian official told Reuters that Nasrallah’s death prompted authorities in Iran to thoroughly investigate possible infiltrations within Iran’s own ranks, ranging from the powerful Revolutionary Guards to senior security officials.
Tehran grew suspicious with a member of the Guards who had been travelling to Lebanon, he said. Concerns were raised when one of these individuals began asking about Nasrallah’s whereabouts, particularly inquiring about how long he would remain in specific locations, the official added.
The individual has been arrested along with several others, the official said, after alarm was raised in Iran’s intelligence circles. The suspect’s family had relocated outside Iran, the official said, without identifying the suspect or his relatives.
Another source said that Nasrallah’s assassination has spread mistrust between Tehran and Hezbollah and within Hezbollah. The Supreme Leader “no longer trusts anyone,” said another source who is close to Iran’s establishment.
The suspicion of Mossad infiltration dates back to the time when Hezbollah commander Fuad Shukr was killed in July in an Israeli airstrike on a secretive Beirut location while meeting an IRGC commander, two Hezbollah sources and a Lebanese security official told Reuters at the time. That killing was followed a few hours later by the assassination of Hamas leader Haniyeh in Tehran.
Hezbollah is reeling from Nasrallah’s killing in his deep bunker in a command HQ, shocked at how successfully Israel penetrated the group, sources said.
(With inputs from Reuters)