Police are also using dogs to search for the bodies and three of the missing bodies have been discovered with their help so far, Richárd Prohászka told a press conference. Sonar equipment, search lights and night-vision are also being used, he added.

The search for missing persons started right after the collision and will continue until all the bodies are found, he said.

Other water authorities are also involved in the search, he added. In response to a question, he said the body of one of the Hungarian crew from the Hableány pleasure boat had been found thanks to a citizen’s report on Thursday.

In response to another question, he said there was no plan to involve civilians in the search operation.

The national water management authority said on Friday that the water level of the River Danube was still on the rise.

Snow melting in the catchment areas of the river is expected to push the water level a few centimetres up in the next few days.

A flood alert is in place along 350km of the river in Hungary, the authority said in a statement.

At a time to be determined on the basis of forecasts, Slovak authorities are expected to inhibit the river flow over the period of four hours in the near future, the authority added.

The water level was 466cm at 10am on Friday and it is expected to drop to below 400cm next Wednesday evening only, it said.

Slovakia is helping to speed up lowering the water levels of the River Danube with a view to aiding the operation to raise of the wreck a National Water Directorate (OVF) spokeswoman said on Thursday.

Gabriella Siklós told public television channel M1 that the OVF had turned to its Slovak counterpart with a request to inhibit flows upriver so as to speed up the ebbing downriver.

The large crane will then be able to approach the wreck and begin to raise it.

MTI Photo: Mohai Balázs