The German bank - which has its UK headquarters in Canary Wharf - is believed to be looking at its options should Britain leave the EU.
However, a spokesman for the bank told the BBC that it is “early days and no decisions have been made”.
It was announced earlier this month that Deutsche Bank made an offer to sub-let 350,000sq ft at 10 Upper Bank Street, where it has a sub lease from Clifford Chance until 2028.
The bank - which employs 9,000 people in the UK - is the first to announce it is formally examining the potential fallout from the referendum, according to the Financial Times.
Many businesses have urged the Government to bring forward the referendum.