Allegations have surfaced that some Balfour Beatty employees were involved in a corruption scandal over gas mains contracts in the West Midlands.
It is said they allegedly exchanged “wads of cash” and even holidays for giving work to subcontractors.
The issue involves a gas distribution strategic partnership (GDSP) covering gas mains replacement work in the West Midlands.
Balfour Beatty runs this partnership as well as another in the North West on behalf of National Grid. It has an eight year contract worth about £4 billion for the two projects.
Concerns were raised when the union GMB which represents energy workers flagged up the possible “corruption”.
Gary Smith, GMB National Secretary said: “I am told that the investigation underway is into allegations of bullying, mis-reporting, fraud and corruption. We understand that gas mains replacement work, running into tens of millions of pounds in value, may have been tainted by allegations of corrupt practice.”
Balfour Beatty confirmed it has been investigating “allegations of improper conduct” for the past few months.
It is looking into “localised behaviour by a small group of individuals” working for Balfour Beatty involved with sub-contracting.
The firm has suspended three middle-managers working on the West Midlands contract during the investigation.
National Grid confirmed it was working with its contractor to look at the “inappropriate activity” but said it would not be appropriate to comment further at the moment.
However the union has called for more “clarity” on the matter from Balfour Beatty.
Mr Smith added: “We do require some clarity on what the extent of the corrupt practice is likely to be… what value of work was carried out following or as a result of alleged back-handers?”