A 21-year-old railway worker was hit and killed by a train in Battersea because a construction company and a recruitment agency failed to train him properly, a court heard.

Balfour Beatty and McGinley Recruitment Services pleaded guilty at City of London Magistrates' Court last week to failing in their duty to ensure Michael Mungovan was not endangered while at work and failing to make sure he was informed properly about his hazardous work.

The victim's father, Danny Mungovan, plans to attend an Old Bailey hearing where the two companies could face "unlimited" fines.

Michael Mungovan, from County Cork in Ireland, was earning holiday money as a casual railway worker.

The Brunel University student was working with a colleague on the line in Nine Elms, just outside Vauxhall station, after midnight on October 9, 2000.

They were trying to bring a section of track out of use so maintenance work could be done.

But Mr Mungovan, who was walking between two live rails on the wrong line, was hit from behind by a train travelling at 50mph.

His colleague Hamilton Hempstead did not have supervision training. And Mr Mungovan's family said he had received just nine hours' training and did not hold a valid track safety card. He had been in the job just three days.

Directors and managers from both firms were in court last Wednesday.

But both refused to accept Mr Mungovan was classed as an employee of either company, saying: "We seek to make clear it does not set any kind of precedent about people employed through agencies."

The Health and Safety Executive accepted their guilty pleas under Section 3 of the Health and Safety at Work Act, which relates to duties towards non-employees.

But it agreed to drop charges under Section 2, which relate to more rigorous duties towards employees.

The decision means no precedent has been set to clarify the status and rights of casual agency staff.

Mick Holder, of health and safety pressure group London Hazards Centre, said after the hearing: "This should have been a manslaughter trial.

"That's the only way if someone is found negligent that someone could be given a prison sentence, which is the right sentence for a crime as serious as this one."