They will join two full-time officers from the Arts and Antiques Unit of the Metropolitan Police Service (Met), patrolling antiques markets and
art dealerships, as well as participating in undercover work.

Staff from the Art Loss Fund, the British Museum (BM) and the Victoria and Albert Museum will be taking part in the scheme. They will have 18 days of intensive police training at Hendon, which will include restraint techniques, arrest and life support, followed by two days of specialised training on arts and antiques. Once trained they will undertake 26 shifts a year (or one day a fortnight) with the Met.

The scheme was started after the Met told the Arts and Antiques Unit that it would have to cut costs by 50 per cent by 2008. At present, the unit costs £350,000 a year to run. The museum volunteers will be sponsored by their employers and given paid leave for the days that they work as special constables, and it is hoped that this will help to save the Met about £170,000 a year.

According to a Met spokeswoman, the Art and Antiques Unit is also in discussions with two interested parties about sponsoring the unit to meet the cost of the cuts.

Neil Barrett, the head of Metropolitan Special Constabulary Employer Support, refuted suggestions that the move was privatising the police force by the back door. Special constables would not generally be on duty at their place of work, he said, unless they were specifically called there or there was a big operation.

However, in a pack about the scheme sent out to prospective organisations, the Met describes the initiative as 'a risk-free, low-cost investment in security', promising 'police-trained (and empowered) staff working in your buildings, doing their "day job" when not on duty with the Met'.

Employees are being enticed onto the scheme with the promise of free travel on London's tube, buses and DLR. There is an annual boot allowance and female officers also receive a monthly stocking allowance.

Michael Lewis, the deputy head of portable antiquities and treasure at the BM, began his training for the scheme last month. He said the real lure was the opportunity to 'raise the profile of archaeology at the Met'.

'We don't always understand what makes the police tick,' he said. 'It would be useful to know how they think, and what they think is important. Archaeologists have always complained about the police not taking them seriously, and this is a chance to redress that.'

Antonia Kimbell, the art trade manager at the Art Loss Register, is also taking part in the scheme. She said it is 'an extremely good initiative', although she is worried that she may be 'never quite off duty'. Once trained, special constables are expected to carry their warrant cards at all times.

Patrick Steel