Mr Jacob Adokor, Director of Tema Port, who gave the caution, said the Authority frowns on acts of stealing, fraud, drunkenness and conniving and abetting.
Mr Adorkor added that security personnel are not allowed to grant unauthorised media interviews.
The Director of Tema Port was speaking during a review of the passing out ceremony of 189 GPHA security recruits.
He noted that the recruits who would be assigned to different posts at the port would be expected to contribute their quota to the Authority in achieving its aim to be the best port in West Africa.
Mr Adorkor encouraged the security personnel not to lose focus because of challenges they would encounter on the job.
A total of 189 recruits consisting of 60 females and 129 males passed out after seven weeks of rigorous training at the Army Recruits Training School (ARTS) at Shai-Hills in the Shai Osudoku District.
They received training in first aid, voice procedure, drill, security intelligence, customer relations, port lessons and weapon handling among others.
Prizes comprising cash, leadership book and certificates were presented to Miss Kelly Florence for emerging best female recruit, Mr Akurgo Coleman, best in drill, Mr Antwi Bosiako Foster, best in leadership and Mr Ahli Godwin Kwami overall best recruit.