DUBAI  - Dubai's financial services regulator's probe into collapsed private equity firm Abraaj is focusing on the firm's senior management and people who may have failed to identify or report irregularities, it said on Tuesday.

"We will use all of our powers to deal with those who are found to be culpable," the Dubai Financial Services Authority (DFSA) said in its annual report.

DFSA has been investigating Abraaj Capital Ltd, an entity of the collapsed firm, over a range of matters.

"This investigation is highly complex, on a wide scale and is being pursued vigorously," the regulator said on Tuesday.

"We are focusing our attention on senior management responsible for the conduct of the affairs of the relevant companies and funds, and persons who may have failed in their responsibilities to identify or report irregularities."

Abraaj, which filed for provisional liquidation in June 2018 in the Cayman Islands, was the largest buyout fund in the Middle East and North Africa until it collapsed last year after a row with investors over the use of money in a $1 billion healthcare fund.

U.S. prosecutors have charged several senior executives of Abraaj including its founder Arif Naqvi with criminal charges, accusing them of taking part in a massive international scheme to defraud investors.

Naqvi, who is in London and on bail, will face a court hearing for an extradition to the United States next year. Naqvi has denied any wrongdoing through a public relations firm that represents him.

DFSA had said in April it was in touch with the U.S. Securities and Exchange Commission about the latest case involving Abraaj. 

(Reporting by Saeed Azhar Editing by Keith Weir) ((Saeed.Azhar@thomsonreuters.com; +971 44536787; Reuters Messaging: saeed.azhar.reuters.com@reuters.net))