Russian state-owned television channels accidentally aired footage of a "secret" new weapon system presented at a defence meeting chaired by President Vladimir Putin this week. 

Kremlin admitted that certain "secrets" were caught on camera from the defence meeting on Tuesday, and the footage has been deleted. 

"Certain secrets were indeed caught on camera. That is why later they were deleted. In future, we will certainly take preventive measures not to let it happen again," said Russian presidential press secretary Dmitry Peskov on Wednesday, according to TASS news agency.

While it is not clear from Russian media reports what the new weapon system was, screenshots of the TV footage shared online showed a defence official holding a plan of what looks like a drone submarine. 

According to The Guardian, the weapons system was the Status-6, designed by a nuclear submarine construction company in St Petersburg.

The Daily Beast has reported that it was a drone submarine that can carry a "radiation-scattering dirty bomb". 

The article also suggested it could only be a propaganda move by Russia to suggest it was building a dangerous new weapon. 

Russia's Sputnik International had reported last month that Russia was developing "next-gen nuclear submarines" that would be produced by 2017-18. 

The video below is the purported footage of the Russian defence meeting, which shows Putin sitting along with military officials. One over-the-shoulder camera shot (at 1:46) shows an official looking at a detailed plan of a weapons system.