Ms Lenicker, 29, parked her car in the Homer Tunnel carpark in Fiordland before beginning a tramp on March 30, and did not return.
Friends in Nelson reported her missing on April 10 when they had not heard from her.
Police and search and rescuers have since searched the Homer Tunnel and Gertrude Saddle areas.
Earlier police said the man may have spoken with Christine about her travel plans and where she was planning to hike.
Today, police thanked all those who helped to identify the man, and in particular a tramper who came into the Stratford police station.
Ms Lenicker has not been seen for more than two weeks after she parked her Toyota Odyssey at the Homer Tunnel car park to begin tramping in the Fiordland National Park on March 30.
Ms Lenicker set off on the Gertrude Saddle Route - an ''expert route'' expected to take 4-6 hours return, according to the Department of Conservation website.
She never returned to her vehicle and police were alerted by friends of the woman in Nelson.
''The information we have got suggests she is still in the area,'' Det Sgt Kean said.
Although police hoped to find Ms Lenicker safe and well, grave concerns were held for her safety.
''It's over two weeks now [since she was last seen].''
In the past fortnight, there had been torrential rain and near-freezing temperatures.
A helicopter searched the area for about an hour on Tuesday.
Police would use a helicopter to search again, but were waiting for snow to melt.
The terrain in the area was not suitable for ground searches.
Ms Lenicker did have hiking ability, but it was unknown how prepared she was if she got into difficulty.
It was not known what Ms Lenicker was wearing when she went missing.
She arrived in New Zealand on March 8.
Police were in contact with her family and the German Embassy, Det Sgt Kean said.
Police urged the hitchhiker or anyone who knew him to contact Te Anau police on (03) 249-7600.
