Staff at BTC have been calling in sick in what bosses believe could be industrial action.A spokeswoman for the firm issued this statement this morning: “Since Friday June 29, 2012, BTC departments have been affected by a large number of absences due to sickness."Whilst we believe that the unusually high number of absences may have been the result of some industrial action, BTC has continued to make every attempt to resolve this matter through on going discussions with Bermuda Industrial Union Officials."BTC recognises the impact sickness have on our customers and wishes to apologise for any service interruptions that may have occurred.”