Troubled St Peter's House is being sold to a South Asian arts group in a secret deal.

The prestigious building in Forster Square, which once housed the failed £5 million Life Force faith museum, is close to being signed over to the Kala Sangam Asian arts company even though it has never been put up for sale on the open market.

And the Telegraph & Argus understands that the group is all set to acquire the landmark former main city post office for an apparently knockdown price of less than £500,000.

The disclosure has prompted a leading councillor to call on Bradford Council to investigate the deal.

Kala Sangam has apparently been in negotiations with the Millennium Commission to buy the building for two years even though would-be developers had no idea it was up for sale. The group is armed with a £1.5 million Arts Council award and says it wants to create a "centre for excellence for South Asian and collaborative arts."

It says there would be space for performances, workshops, dance and music studios, gallery space and offices. The Millennium Commission took over the title of St Peter's House from the Cathedral after the collapse within months of Life Force, which had received a £2.2 million grant and sent Bradford Cathedral to the equivalent of bankruptcy.

The Commission said today the transaction to sell the building to Kala Sangam was now in the hands of lawyers, with completion expected this month.

Neither party would comment on the price but the Telegraph & Argus understands it is up to £500,000. All proceeds will go to the Millennium Commission.

The building is designated for retail in the city's proposed master plan, but was not put on the open market.

A Commission spokesman said it had wanted a project for the "public benefit" and would have clawed back the grant to Life Force if it had not been possible to get the preferred option.

She added: "A user emerged which could maintain that preference. The building didn't lend itself to the open market place because of problems like access and VAT. But we are content we got open market value."

The Commission spokesman refused to say how much the building had been sold for on the grounds of commercial confidentiality.

It is understood £1.5 million of the grant to Life Force remains unpaid to the Commission.

Cathedral administrator Michael Leeming said: "Upon default the title of St Peter's House went to the Millennium Commission. The Cathedral has no say on the sale or future use of the building."

Bradford Council has a lease on the ground floor of the building which ends in 2025.

Assistant interim chief executive Alan Dalton said: "The ground floor is used as our Centre for Learning and is occupied by the human resources department - employee, organisation and development.

"Should this sale proceed, this company would become the Council's landlord. We are discussing with Kala Sangam its proposals for the building."

Councillor Jeanette Sunderland, leader of the Council's Liberal Democrat group, said she was asking for the whole issue to go to the authority's regeneration and economy committee.

Coun Sunderland, who sits on the steering group of Regen 2000 - the organisation spearheading the rebirth of that area of the city - said the committee should examine all aspects of the deal.

She said: "The Council is clearly an interested party because we have our training based in St Peter's House.

"The sale has clearly been a protracted business. I was never aware the property was being sold and I believe it should have gone on the open market. There appears to have been secrecy.

"This is a flagship for the city which must not be allowed to fail. There have been huge amounts of money put into two projects. My concern is that this time the finances must stack up."

The collapse of the Life Force project created a vicious circle because the Cathedral remained responsible for the maintenance of the mainly empty Grade Two listed building.

As a result it fell into disrepair despite the huge sums poured into its redevelopment.

That means large amounts will also be needed for maintenance when the arts group moves in.

The former Royal Mail building designed by Sir Henry Tanner and built in 1886 is expected to house the first centre of its type in the north of England when Kala Sangam moves in.

And the Arts Council has said its award recognises the group's well deserved reputation for South Asian arts.

The Dean of Bradford, the Very Reverend Dr David Ison, welcomed the news the sale was imminent.

He said a company voluntary agreement set up because of the financial crisis meant the Cathedral was technically a "discharged bankrupt."

He said: "It is frustrating and means we cannot enter into any projects.

"We are extremely anxious to get it resolved. When the sale is resolved the proceeds would go to the Millennium Commission. The company voluntary agreement will end and the Cathedral will be able to develop without financial constraints."

Kala Sangam's programmes manager Ajit Singh said: "The purchase price for St Peter's House is being negotiated."

He said they would work with their architects on the development and had no clear timetable yet.

Bradford Council's executive member for regeneration, Councillor Simon Cooke, said: "This is good news for everyone concerned. It has taken a long time."

Bradford Council's group planning manager David Preece said St Peter's House was earmarked for possible retail in a planning blueprint for the markets quarter of the city which was out to public consultation. But he stressed shopping was only a proposal put out for public comment.