Per Tass, the Russian News Agency (https://tass.com/world/1520571),
Gazprom already found NATO explosive devices on Nord Stream in 2015 — spokesman
On November 6, 2015, the NATO Seafox mine disposal unmanned underwater vehicle was found during the scheduled visual inspection of the Nord Stream 1 gas pipeline
MOSCOW, October 10. /TASS/. An incident with NATO explosive devices occurred earlier at the Nord Stream gas pipeline, official spokesman of Gazprom Sergey Kupriyanov said on the air with the Rossiya-24 TV Channel.
“It is necessary to remind about developments at the Nord Stream gas pipeline that were already registered earlier. This case is well known. On November 6, 2015, the NATO Seafox mine disposal unmanned underwater vehicle was found during the scheduled visual inspection of the Nord Stream 1 gas pipeline. It lay in space between gas pipelines, clearly near one of strings,” Kupriyanov said.
“NATO said the underwater mine disposal vehicle was lost during exercises. Such NATO exercises when the combat explosive device turned out to be exactly under our gas pipeline,” the spokesman said.
The explosive device was deactivated by Swedish Armed Forces at that time and gas transport halted due to the emergency resumed, he added.
And, here is one of the photos
For those interested in the Seafox, here’s the company’s website: https://www.atlas-elektronik.com/solutions/mine-warfare-systems/seafoxr.html
The Seafox is an anti-mine remotely operated vehicle (ROV) manufactured by German company Atlas Elektronik to locate and destroy ground and moored mines. There are two versions and a training version. The orange Seafox-I “inspection” variant has sonar and an Inertial navigation system, and the black Seafox-C “combat” round has a 1.4 kg shaped charge warhead. The system is in service with eleven navies across seventy platforms.The SeaFox is an advanced design of an Expendable Mine Disposal Vehicle or EMDV. The SeaFox comes with a control panel to help the user locate and destroy the mines. The SeaFox has a low life cycle cost meaning it has very low maintenance costs and does not cost much to rebuild if destroyed. The main target for the SeaFox is unexploded mines that pose a danger to ships and other vessels that might travel along the route. The SeaFox communicates with the ship via a fiber-optic that connects into a TV for the captain to view the mine. The Seafox also has a special launcher and retrieval system that it uses. Together the console and launcher help navy’s around the world conduct damage estimation, route surveys, maritime boundary control, intelligence and harbor surveillance missions. The SeaFox primarily uses a transponder called dead reckoning. Dead reckoning is a pressure sensor on the SeaFox. The Seafox Drone has also been used on the MH-53 helicopter.
Countries operating the Seafox include the United States, United Kingdom, Estonia, Finland, Germany, Netherlands, Sweden, Belgium, and Japan.
Note: the MH-53 helicopter is used by US Navy antimine helicopter squadrons such as HM-12 asn HM-14. These anti-mine helo squadrons were reactivated in 2015.
Here are several US Navy HM-12 and HM-14 websites: