Detectives investigating the death of British student Isabel Peake say the main suspect has been spotted recently in Marseille.

The news came after they joined forces with their counterparts in Dijon, who are hunting the murderer of another French woman on a train.

Corrine Cailloux, 36, was found slumped in the toilet of the Calais-Ventimiglia sleeper service in the early hours of Tuesday.

She died from multiple stab wounds, including cuts to her throat, having been attacked while her six-year-old son slept in a nearby compartment.

The 20-year-old male suspect, of Algerian origin and named by French media as Sid Hamed Rezala, was reportedly released from jail in June after serving a sentence for sex offences.

Police said on Thursday he had been seen in Marseille in the previous 48 hours.

The battered body of Ms Peake was found lying by the side of the main railway line 75 miles north of Limoges on 13 October after either falling or being pushed from the Brive to Paris express.

Officers in Dijon confirmed they were still hunting Sid Hamed Rezala, who is said to closely resemble an e-fit issued by police seeking the murderer of Ms Peake.

Hopes for arrest

A Dijon police spokesman did not confirm Rezala's name, but said: "This man has not yet been arrested but our investigation continues. We believe we have identified him fully and hope that an arrest could come quickly."

Detectives were able to identify the suspect, who has a record for petty crime on trains, after his name was taken by an SNCF inspector for travelling on the Calais-Ventimiglia train without a ticket.

He is also thought to resemble a man seen talking to Ms Peake before she boarded the train at Limoges and according to French media reports may also have had his name taken for not travelling with a ticket on that train.

The arrest of a suspect would be the first major breakthrough in the Isabel Peake inquiry, which has been criticised in Britain for apparent delays.

Isabel, from Barlaston, Staffordshire, was on an exchange programme at the University of Limoges and was travelling back to the UK to visit her parents and boyfriend when she was murdered.

Isabel's parents, Anne and Brian Peake, plan to keep up the pressure on the French police in the wake of the latest killing.

They have criticised the initial handling of the case, complaining about a wall of bureaucracy.