Deloitte was called in by Doyle Group’s bank yesterday and placed the whole group into administration this afternoon after going over the books.

Deloitte said it was too early to make a statement about the business but administrators will now look at selling the group assets and plant.

The administration puts around 400 jobs at risk.

Doyle Group consists of three operating businesses, the core concrete frame specialist John Doyle Construction, fit-out firm Ibex Interiors and Blythewood Plant.

Like the rest of the concrete sector Doyle Group suffered as orders dried up in the downturn, and saw turnover shrink by a third to £79m in 2010.

The news came as rival concrete firms said they had started to receive calls from John Doyle workers.

The industry has been alight with rumours about the firm all week and the Enquirer has fielded a string of concerned calls about the company.

One London concrete contractor said: “We started to get calls on Tuesday from staff saying they were worried about their jobs.”

“There seems to be a lot of people looking for work at the moment.”

Doyle Group is run by well-known construction personality Stef Stefanou OBE.

Seventy-year-old Stefanou stepped away from day-to-day operations several years ago but was forced to return from semi-retirement to run the business again after the management’s push into general building ran into difficulty.