Britain's £5bn-a-year scrap industry is facing tougher regulation as part of a government crackdown on metal theft.
People selling scrap could be required to register and face identity checks.
And cash payments could be banned, to make metal transactions easier to trace, Home Office minister, Lord Henley told the BBC.
Tougher regulation would be welcome according to an industry spokesman, but a cash ban could be counter-productive, he warned - encouraging illegal trades.
Hospitals, the rail network, utility companies, churches and war memorials have all been targeted in recent years by thieves attracted by the rising prices of non-ferrous metals such as copper.
"I think it likely that we will have to regulate," said Lord Henley, the Home Office minister responsible for crime prevention.
"We will have to improve the 1964 Scrap Metal Dealers Act which colleagues have been saying is well past its sell-by date."