Train surfer dies after falling from train in Brisbane's south

A man has been killed after train surfing in Brisbane's south, causing major delays as commuters made their way home.

Police say the man in his 20s was caught on CCTV footage spray-painting and train-surfing near Runcorn Station before he died just after 1.30pm today.

"Our initial enquiries again suggest he was train surfing and possibly graffiting the rear of the train," Ian Cameron from Queensland Police said.

"It's a tragic waste of life and such a it's a senseless act."

Train services were suspended in both directions causing delays all afternoon.

A Queensland Rail spokeswoman said their own response units were also investigating.

"We are working with police to investigate the incident and we are unable to speculate on the circumstances," the spokeswoman said in a statement.

Additional reporting by AAP