Railtrack's insurers are suing the driver who caused the Selby rail crash for £11m.
Newspaper reports said a High Court writ was served on Gary Hart in prison last month, demanding compensation for damage and lost business caused by his alleged negligence.
Last February, a Great North Eastern Railway express train hit Hart's Land Rover on the east coast main line near Selby, North Yorks. Hart had fallen asleep at the wheel. It is understood that AIG is one of Railtrack's principal insurers. AIG refused to comment on the writ or its relationship with Railtrack.
Fortis Insurance, the company that insured Hart's car, said the writ was normal procedure and was expected.