After the mysterious crash of a plane in the Baltic Sea, Latvian emergency services continue to search for the missing occupants.

After several pieces of wreckage and debris from the crashed machine were recovered from the sea, the rescuers have now also found human body parts near the crash site.

The remains have been handed over to the criminal police for further investigation, the spokeswoman for the Latvian Navy, Liva Veita, told the Leta news agency on Tuesday.

The head of the Latvian sea rescue coordination center, Peteris Subbota, also confirmed the find, which was made on Monday evening before dark.

The private plane flew over the Baltic Sea on Sunday on its way from Spain to Cologne.

There it crashed into the sea in the evening off the coast west of the Latvian port of Ventspils.

Communication with the Cessna 551 with four people on board had been interrupted for a long time before the accident.

The identity of the passengers has not yet been officially confirmed.

The systems engineering company Griesemann from Wesseling near Cologne had announced that the four missing persons were the company founder Peter Griesemann, two family members and one other person.

Ships of the Latvian Navy and the Border Guard are used for sea searches.

On Tuesday, the rescue workers began to search under water with the help of drones and special equipment.

Work is expected to continue in the coming days, Subbota said.

According to him, the aircraft, which was registered to an aviation company belonging to the Griesemann family, may not have a black box.

This could make it more difficult to determine the cause of the crash, which has not yet been clarified.

Griesemann is a Rhenish medium-sized company that claims to have more than 1,600 employees in Germany, Austria and the Netherlands and that works in lightning protection, among other things.

The current company boss is the son of the founder, who retired in 2015.

The news of the possible death of Griesemann, who is also active as a carnival participant, triggered sadness and horror in Cologne.

Mayor Henriette Reker was dismayed by the "tragic accident" in a message to the family.