The crew of an oil-laden ship which collided with the Channel wreck of the Tricolor may not have known of the impending danger, it has emerged.

We do not understand how it is possible Hunter Rouselle, French Navy

French coastguards said those in charge of the Vicky, which got stuck on the car transporter for several hours on News Years Day, seem to have been unaware of the floating hazard, lying off the Kent coast.

Michaud Philippe, a French Coastguard duty officer, said inquires were continuing but revealed: "The captain will be interviewed by the Belgian Maritime Authority but, at the moment, we know the Vicky seems not to have been informed there was a wreck."

Commander Hunter Rouselle, an officer with the French Navy, said the crew had many opportunities to pick up radio warnings.

He said: "We do not understand how it is possible.

"We say by radio, by written message there is a wreck at that point.

	:	Graphic guide
The Tricolor shipwreck

"This information has also been provided to all ships by specialist services."

The Tricolor originally sank with its cargo of 3,000 cars after being hit in thick fog by the cargo freighter Kariba on 14 December.

It was hit two days later by the ship the Nicola.

A preliminary investigation by the Belgian Authorities is said to have found a number of holes in the Turkish-registered Vicky during an inspection on Thursday.

But very little of its 70,000 tonne cargo of flammable oil has escaped.

A small leakage of 300 metres long and 30 metres wide "will disappear naturally" causing little pollution, French authorities said.

Adequate warnings

Mark Clark, a spokesman for UK Coastguard, told BBC News Online it was impossible to believe the crew of the Vicky had not picked up a warning.

He said: "There are enough beacons emitting signals to say they were clearly not listening to the radio."

Mr Clark said the final sequence of events would be established by the joint French and Belgian investigation.

Collision dates

December 14: Tricolor collides with Kariba December 16: The Nicola hits the submerged Tricolor January 1: Cargo ship the Vicky runs onto the Tricolor

Wednesday's incident has raised further questions about whether warnings to passing ships about the wreck in one of the world's busiest shipping channels were adequate.

Buoys and emergency guardships remain in place around the wreck of the Tricolor and hourly radio warnings are being broadcast to shipping.

The maritime union Numast said ship owners were cutting crew levels and demanding excessive working hours, although there is no suggestion that was the case with the Vicky.

Union spokesman Andrew Linington said he was "appalled" to hear about the latest incident.

He said 90% of such incidents were the result of the human factor.

'Drive to reduce crewing levels'

"There is a constant drive to reduce crewing levels and people can be working 80 to 90 hours a week on busy waterways like these," said Mr Linington.

The Vicky, built in 1981, is a single-hulled, double bottomed vessel - meaning it has an extra layer of metal around the base of the hull.

The 243 metre-long, 43,000 tonne tanker was en route from Antwerp in Belgium to New York when it struck the Tricolor.

The Vicky's captain is continuing to transfer cargo from the damaged tank before setting off for a Belgian port for repairs.