Lebanese families of victims of the Beirut port explosion are holding out hope after investigators and rescue workers found what appears to be an “underground emergency shelter,” according to reports, despite denials by the government of their existence.

According to a report by Sky News’ Alex Crawford, rescue workers scouring the wreckage of Tuesday’s explosion found what seems to look like an underground emergency shelter that may have been built decades ago as a sort of “panic room.”

“They are praying Ghassan has somehow managed to survive by taking refuge in an underground emergency shelter which was built decades ago as a secure “panic” room in the event of bomb attacks or disasters,” Crawford said in her report.

A photograph of the missing silo employee Ghassan Hasrouty pictured with his wife Ibtissam in the family home, following Tuesday's blast in Beirut's port area. (Reuters)

Ghassan Hasrouty is one of dozens of workers who were at the port on Tuesday when an initial fire led to an explosion due to the storage of more than 2,000 tonnes of ammonium nitrate. Hasrouty had worked at the port for more than 38 years as the head of the operations room for a company that managed the silos of corn at the port.

The Lebanese army on Sunday denied the existence of “suspicious tunnels” at the port of Beirut.

Family members of Ghassan Hasrouty, a missing silo employee, watch a news channel on television as they wait for information, following Tuesday's blast in Beirut's port area. (Reuters)

Hasrouty’s family believes that he and six of his colleagues are somewhere under the silos and they are holding out hope that they are alive.

They say the rescue response has been too slow and disorganized and that whatever chance there was for finding them alive is being lost.

The family says that despite giving the authorities the exact location of where he was believed to have been at the time of the explosion, the rescue effort did not start until 40 hours later.

“These people who are missing are not just numbers,” says Elie, Hasrouty’s son, told Reuters.

“We need to highlight the mediocrity of management of this disaster, of this situation, how bad it is managed... not to repeat such a horrible disaster and horrible management.”