Abu Dhabi’s Al Hilal Bank uncovered internal fraud worth more than 500 million dirhams ($136 million), according to people with knowledge of the matter.

Some employees at the Abu Dhabi state-owned Islamic lender allegedly withdrew funds from dormant customer accounts, said the people, asking not to be identified because the details aren’t public.

Money was then transferred from the Al Hilal accounts to bogus accounts before being withdrawn, they said.

A total of 38 people from Asian and European backgrounds were arrested last summer for the "unlawful confiscation" of 635 million dirhams from a UAE bank, Abu Dhabi’s Judicial Department said in an emailed statement, without identifying the lender.

The case is being heard in court and those being tried include some bank employees and others who aren’t. Police and the central bank were able to retrieve 625 million dirhams of the money taken, according to the statement. A spokesman for Al Hilal didn’t respond to requests for comment.

Al Hilal is working with banks for an Islamic bond sale in the second quarter, people familiar with the matter said earlier this month.