The Strategic Investment Board (SIB) is widely regarded as one of the most influential official bodies in Northern Ireland.

A Government-owned company, its remit involves encouraging private sector involvement in public sector projects.

Media queries about its work are handled by the press office of its parent Government department, the Office of the First Minister and Deputy First Minister (OFMDFM).

Details of the SIB's spending on outside public relations advisers have been disclosed to the Belfast Telegraph under freedom of information rules.

In 2004-05, it paid consultancy outfit Quo Imus £22,100 for PR services.

During the following year, the cost of public relations work for the SIB by this company rose to a total of £120,700.

In the current financial year, 2006-07, Quo Imus has received £41,650 to date.

In addition, PR services from another company, Geronimo, have so far this year cost the SIB £21,280.

The SIB's FOI response stated that the public relations work included the production and launch of its annual reports and accounts. Printing costs were not included.

The PR bills also covered the publication and launch of the Investment Strategy for Northern Ireland, a keynote document outlining a 10-year £16bn blueprint for the development of public infrastructure in the province.

A spokesman for OFMDFM said: "SIB's communications consultants are employed to provide the company with support tailored to its particular needs.

"The service provided complements the OFMDFM press office service, but does not duplicate it."

The spokesman said the PR consultants had assisted with the management of an "extensive" consultation process on the Investment Strategy.

They had also worked on the production of "effective presentations and other briefing materials that have been used successfully at over 150 events in Northern Ireland, England, Scotland, the Republic of Ireland, America, Canada and European countries".

The spokesman added: "This work has played a significant role in enabling SIB to fulfil its remits to develop markets, foster reform and build bridges between the public and private sectors.

"SIB ensures that it obtains value for money from the work of its consultants, and in this case communications consultants are employed because they bring professional skills and expertise that are not otherwise available."

Established in 2003, the SIB has faced growing controversy on a number of fronts.

One of its architects, former Deputy First Minister Mark Durkan, last year voiced concern at the way its role had devolved under direct rule.

He said the body was supposed to have been a "partnership" organisation involving trade unions and the community and voluntary sectors.

The SIB has been criticised by unions for its focus on Private Finance Initiative schemes. These involve companies taking responsibility for building and maintaining public facilities like schools and hospitals, in return for long-term payments.

There was also condemnation last year of the taxpayer-funded wages of SIB chief executive David Gavaghan.

He received a remuneration package in 2005-06 of £247,882, including a £150,000 salary and a £60,000 bonus.