A Danish inventor has been charged with killing a Swedish journalist that was onboard his homemade submarine when she was reported missing.

The submarine sunk Friday after its owner, Peter Madsen, was rescued by a private boat but there was no trace of the woman. Madsen told police she disembarked the vessel at Refshaleøen in Copenhagen on Thursday night.

Copenhagen police confirmed Friday evening that Madsen had been charged with killing the woman and will appear in court Saturday. Madsen denies the charge.

Drabssigtelse i sag om ubåd https://t.co/vDnLhwxAaF — Københavns Politi (@KobenhavnPoliti) August 11, 2017

Madsen told police after he was rescued in Koge Bay that the vessel sank due to technical problems with a ballast tank.

The female journalist, who has not been named, was onboard the vessel as she was writing a story about the inventor. Her boyfriend reported her missing at 2:30am Friday, according to TV2.

The 18-meter UC3 Nautilus was recovered by the Danish military and divers have reached the site.

Police say it has not been possible, however, to inspect the vessel and they may have to tow it to a port to do so. It’s expected this will not happen until Saturday,

The submarine is considered to be the largest private submarine in the world and was built by Madsen in 2008 after he launched a crowdfunding campaign.

Madsen is the co-founder of Copenhagen Suborbitals, a private non-profit spaceflight organization, but reportedly left the project in 2014.