Northamptonshire Police Authority confirmed a 2.5 acre site, in Pavilion Drive, was the preferred location for the complex and detailed plans are to be submitted to the West Northamptonshire Development Corporation (WNDC) by the end of September.

If it is given the go-ahead, the Criminal Justice Centre would be large enough to house up to 50 prisoners to take the pressure away from overburdened police cells around the county.

Other locations mooted for the centre, including land at police headquarters at Wootton Hall Park and a landfill site in Grange Park, have been rejected by the authority.

A spokesman for the police authority said the Brackmills site was the right location, despite "genuine concerns" highlighted by businesses.

"A new criminal justice centre is needed because existing accommodation is, without exception, in urgent need of modernisation to comply with Home Office standards," the spokesman said.

"The accommodation is also not large enough to house the number of people currently being taken into custody on a regular basis, and is inadequate in terms of the proposed expansion of Northamptonshire.

"Some of the genuine concerns expressed by businesses and users of the Brackmills site and the immediate surrounds relate to what will happen when detainees are discharged into an area which has little public transport.

"The authority expects to be in a position to allay these concerns in the near future."

The spokesman said the selection of Pavilion Drive took into account public concerns about the suitability of the location and promised full and open engagement with people in Brackmills and the surrounding area.

He added: "In selecting the design, they have been conscious of the need for the building to fit into the surrounding business park and are confident that it will be a coherent piece of architecture, which will be widely acclaimed for its design.

The Police Authority confirmed developer Carillion had been selected to prepare detailed plans for the centre, with a final decision expected before Christmas.

A full programme of consultation is planned, including a public exhibition, to address concerns from the public.

Members of the board will discuss the proposals at their annual meeting, a public meeting taking place on Wednesday, April 21, in Brooke House, Bedford Road.