They have been given fresh hope after receiving reports of potential sightings.
Susan, who is originally from Carnoustie, said: “There has been sightings of a confused man saying he is from Scotland only yesterday in a town called Buxtehude.
“The police are sending trail dogs out there again today and we are heading there now.”
Pilice in Hamburg say they believe Liam, who works for Royal Mail and is from Inverness, will still be found alive.
A Facebook page has been set up to raise awareness of the search for Liam.
An online fundraising page has also been set up to help meet the costs of the search for Liam. So far more than £6,000 has been donated.