Safety concerns are mounting in Denmark with the publication of a report showing elderly shadow fleet tankers carrying Russian oil are refusing to let expert pilots on board.

An investigation by the Financial Times and Danwatch has cited leaked internal documents as showing at least 20 vessels have rejected specialist navigators for the dangerous waters connecting the North and Baltic Seas this year.

Danish pilots report these numbers surging over the past four months.

The 20 vessels identified in the report can carry about 10m barrels of oil, according to data company Kpler.

Mikael Pedersen, chair of the Union of Danish Pilots, told the media outlets that all ships used to be “responsible” before the Ukraine invasion.

“[Now] the ships here are typically around 20 years old, perhaps uninsured, the crew is poorly trained, the ships are poorly maintained and now they often sail without a pilot,” he added.

Of the 20 tankers, only three were covered by a recognised Western insurance provider, the report claimed.

The European Union has discussed the possibility of Denmark inspecting tankers without Western insurance carrying Russian oil through its waters.

But this would be a highly controversial strategy.

It emerged only this week that Denmark was investigating a collision involving a shadow fleet tanker en route to load Russian crude.

Unknown ownership

The accident involving the 116,000-dwt Andromeda Star (built 2009), of unknown ownership, took place on 2 March, the Danish Maritime Authority said in a statement to Bloomberg.

The incident remains under investigation, but no further details were given.

The Panama-flagged aframax had been due to load Russian Urals crude on 4 March at the port of Primorsk in the Baltic Sea, according to shipping data.

Instead, the ship headed to a Danish repair yard in Lindoe, arriving on 17 March.

The tanker had left Vadinar in India early in February.