Very grand theft: Barbara Hepworth's park sculpture is stolen for scrap metal

Irreplaceable public artwork is latest item taken in a crimewave sweeping across Britain

The theft of Two Forms (Divided Circle) by Barbara Hepworth has been described as 'devastating' (Getty Images)

A reward was offered last night after an "irreplaceable" bronze artwork by one of Britain's most highly regarded 20th-century sculptors was stolen from a London park.

The Barbara Hepworth sculpture, Two Forms (Divided Circle), is believed to be the latest target in a spate of metal thefts across the country as prices soar. Experts fear that it will be sold for scrap. The theft of the work, which was insured for £500,000, was discovered by a groundsman at Dulwich Park yesterday. The gates to the park had been smashed on Monday night and by Tuesday morning tyre tracks led away from the empty plinth. Southwark Council has offered a £1,000 award for information leading to the arrest and conviction of the thieves.

Peter John, leader of the local authority, said: "The theft of this important piece of 20th-century public art from Dulwich Park is devastating. The theft of public art and metal is becoming a sickening epidemic."

Metal theft is believed to cost the British economy £700m a year. The theft in Dulwich comes a day after Scotland Yard launched a Waste and Metal Theft Taskforce to clamp down on the problem in the capital. Mr John called on this task force to investigate the disappearance of the sculpture.

Ms Hepworth, who died in 1975, is widely considered one of the UK's finest contemporary sculptors. The Two Forms work in Dulwich Park, which was one of six cast, was bought by the Greater London Council in 1970. Ownership transferred to Southwark Council after the GLA was abolished.

This is not the first high-profile theft of sculpture for its metal. In 2005, thieves seized the Henry Moore sculpture Reclining Figure from the grounds of the Henry Moore Foundation in Hertfordshire using a truck with a crane. Police believed the £3m piece was melted down and sold off for scrap for just £1,500.

Stephen Feeke, curator of the NewArt Centre sculpture park and gallery in Roche Court, Salisbury, Wiltshire, said: "Since the Moore theft, everyone has been more alert over outdoor sculpture. People realised the vulnerability of these works and stepped up their security arrangements."

Last month a bronze sculpture of social reformer Dr Alfred Salter was stolen in Rotherhithe. Richard Truman, spokesman for the British Metal Recycling Association, said metal theft was "a big problem, brought on by the global rise in metal prices". Railway lines, road signs, petrol pumps and war memorials have been targeted by thieves. Mr Truman added that thieves often export their stolen goods in container ships or sell them to illegal scrap operations. The price of copper has doubled to £5,000 a ton in the past two years.