Swedish police officers and accident investigators have, however, been allowed on board.
On Thursday, they were present as observers when the Chinese-flagged vessel was inspected in the Kattegat by a delegation connected to the Chinese accident investigation commission.
The vessel is suspected of being involved in two cable breaks that are being investigated as sabotage.
"Have received more information"
Jonas Bäckstrand, deputy director-general of the accident investigation commission, says that the visit has resulted in a clearer picture of what may have happened.
We have received more information about the vessel, its equipment, and the crew has spoken to us, he says.
According to him, there were no restrictions during the time they were on board.
We have been able to do and see what we wanted. We have not compiled all the information from the visit on board, so we have not drawn any conclusions, says Bäckstrand.
China's demands prior to the visit
According to the Police Authority, no investigative measures were taken by Swedish police on board the vessel.
Söderman says that it was one of the conditions set by China prior to the visit.
We were not allowed to send legal assistance either. Then I simply have no jurisdiction.
According to Söderman, it is still unclear whether yesterday's visit to Yi Peng 3 is relevant to the investigation.
It remains to be seen. I have not heard anything about what has happened and if it can have any value, he says.
