Invest NI has not enjoyed a controversy-free life since its formation in 2002.

Its early years saw it dealing with investigations into funding relationships inherited from one of the bodies it replaced, small business agency LEDU.

The saga saw Invest NI's accounts for its first year receive a ‘qualified rating’ — the accountancy equivalent of a rap on the knuckles.

A subsequent Parliamentary probe by the House of Commons Public Accounts Committee centred on Emerging Business Trust, a LEDU-backed provider of loans to fledgling firms.

Businesswoman Teresa Townsley had been a member of Invest NI's first board and a leading figure in Emerging Business Trust.

In a report in 2006 the Public Accounts Committee said there had been “extensive” conflicts of interest in Mrs Townsley's roles.

It was also revealed during the probe that three other Northern Ireland companies were the subject of separate investigations. The findings from these cases have not yet been made public but are expected to eventually be examined at the Assembly.

The most prominent of the three companies was the Bioscience and Technology Institute, a failed medical research initiative established in 2000.

Earlier this month Sinn Fein MLA Paul Maskey tabled an Assembly question seeking details of Invest NI grant offers to firms linked to current members of the quango's board.

Invest NI has described such payments as “inevitable” given the fact that local business people will be on its board.

It has also stressed that the grant decisions go through normal appraisal procedures and are conducted on an arm’s-length basis.

The pitfalls of trying to attract outside investment will, meanwhile, be highlighted in an Assembly report later this week.

It will detail the case of Valence Technology, a US company which was attracted to Co Antrim by the old Industrial Development Board in the 1990s.

Valence relocated its manufacturing operations to China in 2003, having received £15m of public money here.

Some £5.1m of this grant-aid was later clawed back — mainly through the resale of factory premises that had been provided for the company by taxpayers in the first place.