A Lufthansa plane with around 60 family and friends of victims from this week's Germanwings crash left Düsseldorf on Thursday headed for Marseille, where transport to the site of the crash near the French town of Seyne-les-Alpes will be provided.

Family members of Spanish victims are also due to travel to the crash site on Thursday, with many opting to take a bus from Barcelona instead of flying.

"Accommodation in Marseille as well as return flights as needed will be provided by Lufthansa on behalf of Germanwings at the discretion of the individual relatives," a statement from Germanwings read on Wednesday.

The victims' next of kin travel to the crash site as reports are surfacing in several media outlets indicating that one pilot had left the cockpit and was locked out prior to the crash.

Speculation about black box recording

Interviews by the New York Times and other news outlets with sources close to the investigation of the cockpit voice recorder recovered from the crash site revealed that one pilot got up, left the cockpit, and then could be heard knocking to get back in.

"There was no more conversation from that point until the crash," AFP quoted its source as saying.

According to the accounts, the pilot outside the cockpit then tried to break down the door. Up until the pilot left the cockpit, the two pilots could be heard conversing normally in German. It is not clear if the pilot or the co-pilot was the one who had left the cockpit.

No distress signal was sent from Germanwings flight 4U 9525 from Barcelona to Düsseldorf, the source said, and attempts by ground control to contact the plane before the crash were unsuccessful. Before impact, the plane's ground proximity alarm sounded.

Investigation ongoing

Responding to the initial report of the alleged information gleaned from the cockpit recorders, Germanwings issued a statement early on Thursday saying "we have not received any information from the authorities leading the investigation and therefore can neither confirm nor deny the reports of the New York Times. We are working on obtaining more information but will not participate in any kind of speculation."

German Interior Minister Thomas de Maiziere also cautioned against speculation with the investigation still continuing, saying that it was "not helpful" to the victims' families: "I cannot and do not want to comment on this," de Maiziere said.

Remi Jouty, the director of France's BEA aviation agency, did say on Wednesday that "words" had been heard on the cockpit voice recorder recovered at the Alpine crash site in southern France.

An initial analysis would take "a matter of days," Jouty said while declining to say whether the Airbus A320's pilots were conscious as the plane made an unscheduled eight-minute descent before crashing into a mountainside, killing all 150 occupants.

According to Germanwings, they included 72 German citizens, and Spain's government said 51 of its citizens had died in the crash. The numbers aren't quite firm since some passengers appear to have had dual citizenship. In addition, victims from Australia, Argentina, Belgium, Britain, Colombia, Denmark, Iran, Israel, Japan, Mexico, the United States and Venezuela were on board the plane.

Residents of Haltern, a rural town 80 kilometers (50 miles) from Düsseldorf, mourned the loss of 16 high-school students and two teachers in the crash, who were returning from a week-long exchange visit to Llinar del Valles, near Barcelona.

mz/msh (Reuters, AFP, AP, dpa)