A fresh search for a botanist missing in West Africa will begin in the New Year.

Christian Velten, from Brighton, disappeared in March after starting a 4,000km trek following the route of the River Niger.

Christian, 28, was attempting to follow the footsteps of 18th Century explorer Mungo Park through desert, savannah, jungle and swamp.

But he last contacted his family from Kita in Mali on March 23 and nothing has been heard of him since.

Christian's parents, Tim and Pauline, who live in Burwash near Heathfield, are now preparing to spend Christmas without their son.

Mrs Velten said: "Trying to come to terms with the situation is all you can really do.

"You are always living in hope and it is never off your mind. We cannot get on with our lives. The not knowing is the worst bit.

"We have not had any bad news. We felt sure if he had an accident, if he had come to grief, somebody somewhere would know.

"It seems to me he was probably robbed and murdered but nobody has heard of anything.

"We have even interviewed the prisoners in the local prison but nothing has so far turned up."

Last month, a Gurkha employed by the family returned after trying to track Christian, alongside one of his friends.

Although they heard of a number of potential sightings, the majority turned out to be other lone Europeans.

Vicky Paterson, who has co-ordinated the publicity for the search, said: "The team spent five weeks covering road and river along Chris's route between the Mali capital Bamako and Timbuktu to the east.

"The team recorded a handful of sightings of lone white men but most proved to be other Europeans and not Chris.

"However, there are still some unaccounted sightings and these will be investigated in depth by a new search to start in January. The sightings were on the river, and indicate Chris made it through the capital and to the Niger.

"In the meantime, there is still a local man working for the family out there who is looking to verify some of the sightings."

Christian's friend, Alex Bird, from Brighton, said: "In mid-November we held a charity auction for him in London, which raised £16,000 to be used to fund the next search.

"People were prompted to dig deep and it was a fantastic evening. Hopefully, this will come to some sort of end, sooner rather than later."