A search is underway for a Lonely Planet travel writer from Australia who went missing in a remote mountain region in Tibet one month ago.
Mr Lindenmayer is said to be an experienced hiker
Clem Lindenmayer, 47, disappeared after embarking on a solo six-day trek near Minya Konka mountain, also known as the Gongga Shan, in Sichuan province.
He was last heard from on 2 May when he emailed his family before setting off.
His brother and nephew are reported to have left Australia to join Chinese authorities in their search.
Mr Lindenmayer was described in a posting to Lonely Planet's Thorn Tree forum as a "very fit Australian male with a ready smile. He is well-built, approximately 183cm (6ft) tall with grey/brown hair and a short greying beard.
"He speaks Mandarin, German, Spanish and English," contributor Heather wrote, who is said to be a member of his family.
She said his last email was sent to his family in Melbourne from the city of Kangding.
"If he completed this circuit we would have expected him to be back in contact on or about 10 May."
The writer's father, Graeme Lindenmayer, said police in the Australian state of Victoria were liaising with Interpol over his son's disappearance.
He said his son was an experienced hiker who had undertaken similar treks in the past.
"He was going to do what was a pretty standard hike," Mr Lindenmayer told the AAP news agency.
Mr Lindenmayer was not on a writing assignment at the time of his disappearance, a Lonely Planet spokesperson said.
However she added they were in touch with his family and providing support where possible.
The freelance writer and photographer has contributed to Lonely Planet books for the last 10 years, including a guide to surviving in China, Trekking in the Patagonian Andes, and Walking in Switzerland.