The 29-year-old, from Inverness, was on his brother Eamonn’s stag weekend in Hamburg when he vanished in the early hours of 10 February.
Almost a month after his disappearance, pubs around his home city have joined the One For Liam fundraiser between today and Sunday to help volunteers in Germany looking for him.
Eammon said: “It’s been a great reaction. At the last count we had 27 bars just in Inverness. That’s quite a substantial number of bars.
“It’s been an incredible response from the community in general.
“We’re still getting reported sightings of Liam. The last would have been on Saturday.
“We’re hoping through our enormous leaflet drop – 300,000 through the post – that we will start getting them in again.
“I’m keeping hope and remaining positive. We’ve got to remain hopeful that he’s out there and he’s been confused.”
Friends and relatives last saw Liam in the Veermaster Bar and he has been identified on CCTV footage from the Baumwell area after leaving the bar.
A confirmed sighting by his family was announced by The Lucie Blackman Trust last month, saying he had been seen shortly after being separated from the group.
CCTV footage seen by the family shows Liam arriving at the vehicle barrier of the G&J building in Baumwall, Hamburg, about 2:20am.
A witness reports seeing Liam and helping him up some steps to the main entrance of that building after he fell - corroborated by the CCTV.
The footage goes on to show Liam trying unsuccessfully to get into the building before walking towards Michelwiese Park.
He is helped again by the same witness to get into this park and is last seen heading towards the Portuguese Quarter around 2:30am.
Money from the fundraiser will go towards paying for flights, accommodation and other expenses of volunteers who are in Hamburg searching for Liam.
As well as family members, around 400 people in Hamburg have joined the search.
A number of venues in Forres, Invergordon and Nairn are also taking part in the fundraising event.
Tommy O’Connor, who set up the event, said: “Liam and his band played in the pub here, Encore, every Saturday night.
“Since his disappearance we’ve been thinking of ways to support the search campaign and we came up with the idea of One For Liam.
“When a customer comes into the bar they can say ‘one for Liam’ as well and that will go to help the search.”
Any money which does not go towards the search for Liam will go towards The Lucie Blackman Trust, which has been supporting his family.