Police are investigating damage of up to $20,000 caused to the trains when vandals broke in last Thursday night.

Lachlan Valley Railway secretary/treasurer John Healey said it was "grossly unfair" to the volunteer organisation. The trains have been stored under a shed near the Orange railway station for several months after the COVID-19 outbreak suspended their use for tourist train rides.

The train windows were also smashed by rocks in an attack in March.

Mr Healey said they needed to move the trains to their new depot at East Fork where they could be kept behind locked gates.

However, the LVR needs funds to complete trackwork which would enable the trains to be driven into the site.

Following the vandal attack the LVR has received about $4000 in donations toward the project and repairing the damage.

Mr Healey said vandals smashed exterior and interior windows in one of the three carriages.

He said they had also rifled through a first aid box before throwing it onto the ground.

Mr Healey said three 'axle box brasses' had been stolen.

He said they would not be worth much if the thieves tried sell them to melt down but would cost the society about $5000 to replace.

The trains carried the casket of former deputy prime minister and train buff Tim Fischer to his funeral in Albury last year.

"The one that was most damaged was the one that carried Tim's casket," he said.

Mr Healey said the crime had hit society members hard at a time when the coronavirus pandemic had stopped revenue streams.

He said the LVR ran its first tourist train in nine months last Saturday. Mr Healey said the LVR was looking at obtaining government funding for 'shovel-ready projects' to be able to develop the East Fork site as a depot.

It has a main base at Cowra but the line to it has been closed for several years.

Mr Healey said the LVR had also received help from Orange City Council for the project.

Central West Police District acting inspector Luke Cole said forensics officers would examine the trains for fingerprints and DNA.

He said they were also seeking CCTV footage of the area.