He was hired by a Caribbean government to investigate allegations of fraud and soaring development costs which had sparked fury.

But Gerry McCaffrey, a Scottish construction expert, has now found himself embroiled in a political storm after exonerating a senior Trinidadian minister at the centre of the controversy.

Such is the bitterness of feeling being levelled at Mr McCaffrey, he has still to receive payment four months after reporting his findings that have caused consternation and anger within the island's political circles.

Trinidad ministers have also called in to question Mr McCaffrey's fees, after they were alleged to have risen from £20,000 to £300,000, although it is understood Mr McCaffrey denies this figure.

Relations became so strained that when Mr McCaffrey was due to return to Trinidad in March to take part in the inquiry, his flight was cancelled by the Office of the Prime Minister. There are no plans for him to return.

Mr McCaffrey, a director with Glasgow-based Acutus, was the senior planning manager involved in the construction of the £85m Buchanan Galleries Shopping Centre in Glasgow.

He was enlisted by a Trinidad government commission of inquiry to look into the involvement of the island's trade and industry minister Dr Keith Rowley in projects developed by the state-owned company UDECOTT.

But he effectively cleared Dr Rowley of any wrong-doing by telling officials the rising costs of projects were the result of "typos and bad accounting". He found that UDECOTT's filing systems were "appalling".

It is understood ministers have agreed only to pay around £20,000 for his work while they consider whether Mr McCaffrey will be allowed to complete the investigation.

His report has for the time being been placed in limbo as evidence to the commission of inquiry into the Trinidad construction sector scandal continues to be heard.

Trinidad's Minister of Works and Transport Colm Imbert took the unusual step of disclosing the fees of Mr McCaffrey.

But a source close to Mr McCaffrey's investigation told The Herald that the Scot is happy to complete the work he started and feels he has become the victim of political power games in Trinidad. "He is being vilified, heavily clouted, but there is sufficient evidence to show that he has the true story," said the source.

"The government has misquoted and misrepresented him. He did warn them the fees could easily be £300,000 but to date they are half that. He is getting nothing when compared to other professionals who are involved in the process. The government's own lawyer is being paid £100,000 a week.

"While he is aggrieved about what is going on he does not want to say anything because he wants to be above it all."

The source added that Mr Caffrey would continue to work for the commission.

He added: "He takes his job extremely seriously and all he has is his reputation. If they the commission want him out there he will go out there but it is becoming a bit of a side show.

"The allegation is that construction is not procured very cleverly in Trinidad and the indigenous population are gaining nothing from the expenditure of millions of oil dollars.

"He was given a very extensive remit on the commission of inquiry and he barely got started. He put out an initial report and the government has taken umbrage at that report.

"It has escalated to this incredible frenzy.

"What he had done is cleared Keith Rowley. Now he didn't know Keith Rowley. He didn't have any agenda. So that's why the government is taking issue with him.

"They were hoping he would find there was a huge discrepancy that couldn't be explained. But the problem was he explained it and it was down to a complete set of typos, not just one, a number of them and bad arithmetic that could lead people to conclude there was a real problem here."