Police said thieves would have needed a semitrailer and forklifts to steal their heavy haul.

About 140 metres of railway line valued at $6000 was stolen from McCormick's Road in Elmore last Wednesday.

Another 391 metres of line valued at $20,000 disappeared from the Elmore rail yard this month.

V/Line maintenance supervisor Terry Henderson said the railway lines had been stolen after being placed beside the tracks in preparation for the following day's work.

"We have got a security guard to watch our machines at night, but we have rail laid out over 15 kilometres," he said.

"We can't lock everything up."

Mr Henderson said he believed thieves may be using the steel for personal use.

"Because the railway line is so strong, it's good for fence posts and for building sheds," he said.

Mr Henderson said other metal scraps had been stolen from maintenance sites because of its high value.

Goornong police charged a man at the weekend in relation to last Wednesday's theft.

Senior Constable Roger Whitman said another two men had also been charged with stealing metal scraps.

And 391 metres of railway line is still missing.

Sen-Constable Whitman said the thieves would have needed to use a semitrailer and a forklift to steal the missing railway line because of its weight, which he estimated at about 18 tonnes.

Mr Henderson said he hoped the recent charges would deter other people from stealing the railway lines.

"Our biggest problem is that it affects our production and our work," he said.

"It's stealing and we want a stop to it."

Anyone with information about the thefts is urged to phone Goornong police on 5432 2207 or Crime Stoppers on 1800 333 000.