Oil tycoon Ian Suttie has been branded a liar over his involvement in the dismissal of a former employee who raised concerns over "irregular payments".

Michael Gough, a former commercial director at First Integrated Solutions, was constructively dismissed by the firm and has been awarded £78,000 by an employment tribunal.

The tribunal found Mr Suttie's evidence was "less then credible" when he was asked about his involvement in Mr Gough's dismissal, with judge James Hendry adding there was "no doubt" that he was involved "despite his protestations that he was not".

The multi-millionaire was also accused of treating the financial concerns in a "cavalier manner" after he put his hands over his ears when Mr Gough - who received a salary of £125,000 - raised the possibility of fraud with him.

The irregularities related to payments made under the firm's previous ownership.

Judge Hendry awarded Mr Gough a total of £77,967 after finding he was forced to resign due to a string of issues with bosses, including Mr Suttie's reaction to his financial concerns and the businessman's alleged aggressive behaviour towards him in board meetings.

The firm also threatened the director with disciplinary action when he first raised the possibility of leaving.

The tribunal heard Mr Suttie became involved with the firm towards the end of 2013 when he bought a 51 per cent stake in the business.

The existing managing director, Callum Melville, was removed and Mr Gough took on some of the roles of CEO until a replacement could be found.

In a written judgment, Judge Hendry said: "In early 2014 the claimant had become concerned about irregular payments that he had discovered which had been made in 2013."

These related to invoices submitted to Mr Melville's wife which "appeared to be bogus".

Mr Gough raised the issues with his superiors, including Mr Suttie, but "came to understand that Mr Suttie did not want any action taken about the irregular payments".

He later met with the tycoon in June 2014 to discuss the issues.

The judgment states: "He suggested to Mr Suttie that these transactions were a fraud and that the police should be notified. Mr Suttie put his hands over his ears indicating that he was not prepared to listen to Mr Gough."

Mr Gough also found Mr Suttie "difficult and aggressive" towards him and claimed he became so anxious that his health suffered, culminating in a mental breakdown in December 2014.

He also felt he had been sidelined by the firm when a restructure was announced.

He finally raised the issue of leaving in the hope that bosses would make it clear that they wanted him to stay, however, in a move described as "quite extraordinary" by the tribunal, they instead proposed a leaving package and warned he would face disciplinary proceedings if he did not accept it.

The director resigned on December 23, 2014.

Commenting on the witnesses in the case, Judge Hendry said: "Mr Suttie gave evidence and we regret we did not find him a particularly persuasive witness. We found the picture presented by Mr Suttie as to his role in events to be less than credible."

The judge added: "Given the tight grip Mr Suttie kept on the company ... His evidence that he was only told after the claimant's resignation occurred is not believable."

A spokesman for First Integrated Solutions confirmed they are appealing the decision.

The spokesman added: ""First Integrated Solutions rejects that it did not take Mr Gough’s concerns seriously and it has repeatedly stated this position each time Mr Gough has made these allegations."

He also claimed that the financial irregularities related to the previous owners and have been "fully provided for in the audited accounts of First Integrated Solutions".