Shares in Ireland-based Dragon Oil fell nearly 17 percent on Thursday after the company announced an investigation of its supplier procurement procedures, where “possible irregularties” were identified.

The irregularities involve “possible improper conduct between certain former senior managers” from the company’s marketing and contracts departments.

The probe is understood to already have involved police and comes on the heels of an internal audit.

"This matter is completely unacceptable,” chief exec Abdul Jaleel Al Khalifa was quoted as saying.

He said actions were being taken to ensure purchasing procedures were operating properly.

The company said it was delaying an earnings report due in the first days of March pending more on the “alleged irregularities”.

Tags: Dragon Oil Plc