18:06 on Wednesday the alarm came in from a private person. A ferry no longer followed its route but instead steered straight towards a residential area on Lidingö. The circumstances made the event, in all essentials, look rather unimaginative when the ship with a knot drifted towards the properties on Lidingö.

Customer ended in disaster

But: Tomas Åström, crisis and emergency response manager at the Swedish Transport Agency, takes a serious look at the incident:

- It may not happen, but it does anyway. Fortunately, it is very, very rare. The fact that there is a "blackout" is not common on these large ferries, on modern ships it is almost impossible that it occurs. This ship is over 30 years old, he says.

What could have happened if the weather had been worse or there was oncoming traffic on the fairway?

- What might happen ... check out the Costa Concordia. It can turn around simply. It is believed that these ships are unsinkable, but it is not. And not least, it could have ended in an environmental disaster if the ship started to leak fuel.

Transport Authority's suspicion: Russian diesel oil

The report from the Swedish Transport Agency indicates that the culprit in drama is diesel fuel from St. Petersburg, which has now been sent to the laboratory for analysis.

- When the fuel from St Petersburg was mixed with the fuel from Stockholm, some form of jelly was formed which caused a stop. Yes, that's what we suspect, he says.

Despite the responsibility of the shipping company and the flag state, Tomas Åström believes that the authority will follow the matter closely in the future.

- We will keep an eye on this, we know what has happened and can board when we want. If we get the slightest indication that something is strange, we will also do it, he says.

Police confirm that they are investigating the case as a violation of the Maritime Law and have appointed a preliminary investigator.

SVT is looking for the lead investigator for a comment.