"According to Nord Stream estimates, this is a single-use ROV used for the deactivation of old mines," Swedish Armed Forces spokesman Jesper Stolpe was quoted by the news agency as saying.
He added that the device was discovered on Friday during a routine inspection of the pipeline that transports natural gas from Russia to Germany. The pipeline is operated by Nord Stream, a Russian-German joint venture.
According to Stolpe, the militaries of many countries use such devices to deal with the task of demining the Baltic Sea, which is why it is difficult to say who the owner of the device is.
"Right now, the device poses no threat to the pipeline or maritime traffic in the area. But the device can represent a potential hazard if handled incorrectly," Stolpe said.
He also said that the Swedish military contacted Nord Stream AG and ruled out the possibility of sabotage.
As for the Nord Stream pipeline, the project involves Russia, Germany, the Netherlands and France. The natural gas is already supplied via the pipeline's two legs that were put in operation between 2011 and 2012. June 2015 saw the signing of a memorandum on the construction of two more lines of the pipeline. The Russian gas giant Gazprom is implementing the project, along with such companies as E.On, Shell and OMV.