CABLE theft and an "act of vandalism" at a Hunter railway line has caused some trains to go offline, with police now investigating.
The incident at Telarah on Wednesday morning led to a power failure on the North Coast route which could affect commuters until late tonight.
Limited buses were on Thursday replacing passenger trains from Dungog and Telarah, which were terminating at Maitland until further notice.
An Australian Rail Track Corporation (ARTC) spokesperson confirmed "an act of vandalism and theft of cabling" at Telarah was impacting a number of freight and passenger rail services.
"ARTC is working to repair the line as quickly as possible and thanks passengers and freight customers for their patience," the spokesperson said.
All other services are running through the affected section of railway under alternate working processes.
The vandalism was reported to NSW Police after it was discovered on Wednesday morning.
Officers from the Port Stephens and Hunter district, backed by the Police Transport Command, were investigating on Thursday.
The affected cable was replaced and final testing was under way on Thursday.
Normal operations for Dungog and Telarah are expected to get back on track by late Thursday night.
The ARTC has increased its security presence with additional cameras installed through the area.
