Two days after the setting up an expert team to solve the mystery of an obnoxious odor which is bothering the residents of the Iranian capital, the source of the foul smell has not yet been discovered.
While the team has called upon people to assist it in tracing the source, the manager of a building project in the heart of Tehran believes that the source is the building site under his supervision.
"An old septic tank that erupted at the Plasco building site is the source of obnoxious odor that has engulfed Tehran since last Wednesday," a local website, Asr-e Iran cited Ali Rahimi as saying on Thursday, January 3.
The construction team were drilling holes as part of a new structure being built when they apparently hit an old waste disposal septic system sealed years ago.
Plasco building was once an iconic part of the Tehran skyline. The 17-story landmark building was the tallest in Iran at the time of its construction in the 1960s.
The building collapsed on January 19, 2017 during a mysterious fire. It was built in 1962 by Israeli engineers employed by the prominent Iranian Jewish businessman Habib Elghanian, during a decade of rapid growth in Iran. The building was named after his plastics company.
Elghanian was arrested shortly after the Islamic Revolution in 1979, charged with espionage for the "Zionist regime" (Israel) and executed on May 9, 1979.
According to Ali Rahimi, "One of the well-diggers at the site called for help and when we pulled him up, a very repugnant gas with high pressure erupted from the well. It erupted like a volcano for 30-45 minutes with intensity before dying down."
Official sources have not reacted to Ali Rahimi's comments, so far.
The air in Tehran is among the most polluted in the world, the World Bank says. The city is frequently engulfed in smog to the extent that schools in the capital shut down.
The recent foul smell has triggered a series of satirical comments on social media.