Amec was this week presenting evidence at an employment tribunal case brought by Steve Bowcott, the former managing director of its UK construction services business.
The hearing in Manchester follows Bowcott's departure in June last year over allegations of an undeclared conflict of interest.
It is understood Amec claims he gave PR contracts, worth up to £250,000, to a firm owned by Denise Johnstone, whom he married last June. Amec claims Bowcott awarded the work without informing his line manager, the chief operating officer.
Amec called Michael Straughan, the chief operating officer, as its first witness. Amec communication director Richard Shuttleworth and human resources director Ron Lee, are both scheduled to give evidence.
Bowcott, who was unavailable for comment, will present his case on the final day of the hearing next Friday.