The doctor who has requested anonymity told Reuters that serum samples will be sent abroad for further testing.
If the international laboratories confirm the presence of the highly pathogenic H5N1 strain of bird flu, it will be Iran’s first human bird flu deaths.
While official testing is now being carried out, a health official in the northwestern province of Kermanshah could confirm to the news agency ISNA that two people have died showing possible symptoms of the bird flu virus.
"Four people have been hospitalised, among them a woman and her husband who have died. There are suspicions of bird flu symptoms," said the head of the university hospital in the city.
"Their tests have been sent to medical centers inside the country and abroad to clarify the issue," said the official, named only as Dr Izadi.
"Another one of those hospitalised is in critical condition."
Growing concern
In February, Iran announced that 135 wild swans found dead on the Caspian Sea coast had tested positive for the H5N1 in the first cases of the virus to be confirmed in the Islamic republic.
The outbreak came in Gilan province, further north from Kermanshah. That province borders Iraq, where at least two people have died of bird flu.
Iranian health and veterinary officials have been on high alert since January after bird flu struck neighbouring Turkey, with tens of thousands of domestic birds destroyed along the border.