Investigation underway after train derailment on popular Tasmanian West Coast Wilderness Railway

Services from Strahan have been cancelled until the cause of the derailment is determined. (ABC)

Part of a key tourist attraction on Tasmania's west coast has been temporarily closed after a train came off its tracks.

Ninety people were on board a diesel locomotive on the West Coast Wilderness Railway on February 28 when its front wheels derailed.

The heritage railway, which is a major drawcard for visitors to the area, was travelling back to Strahan from the historic Dubbil Barril station when the derailment happened.

"I don't think the passengers really knew what happened, the speeds on the track are very low," said acting general manager of the West Coast Wilderness Railway, Ian Robertson.

"It would have been doing no more than 10 to 15 kilometres an hour."

No one was injured.

Passengers were stuck in the rainforest for hours until another train arrived. (ABC Open contributor no_visible_means)

In light of the incident, all services from Strahan have been cancelled until the cause is identified in a investigation by the Office of the National Rail Safety Regulator.

"Once we can look underneath we'll have more information but until then it's inconclusive," Mr Robertson said.

"Whilst that risk remains, I'm not prepared to reopen services from Strahan."

The Queenstown services are running as normal.

Passengers stranded for hours

The train derailed in the middle of the rainforest, which Mr Robertson said made getting the passengers back to Strahan "a huge exercise".

He said there'd been both positive and negative feedback about it.

"First we needed to get food into them, which is what we did because they were going to be there for a few hours," Mr Robertson said.

"Then we needed to get another train from Queenstown up the rack, over the top and down the other side, then reverse back in and hook on to those carriages and bring them back to Queenstown."

From there, the passengers were taken by bus back to Strahan, about 45 minutes away.

"All in all, it would've been about eight hours," he said.

Mr Robertson said it had been a tough week for staff as they navigated cancellations.

"We're offering people other alternative services in the future, and where we can, putting on extra services in Queenstown," he said.

"People come to the West Coast with the train on their bucket list, so we understand people are really disappointed."

The train had left the Dubbil Barril station (pictured) and was heading back to Strahan when it derailed. (Supplied: West Coast Wilderness Railway)