Luxembourg benefited as nervous investors moved £30 billion (€35 billion) out of UK funds before Britain's initially scheduled March 29 departure from the European Union, according to new research.
In March alone £5 billion of long-term investments flowed out of the UK to jurisdictions within the bloc, financial services research firm Morningstar found.
"In the months leading up to the deadline, investors and fund families became increasingly worried over the impact of an unfavourable deal and its negative implications," Morningstar said.
Luxembourg funds saw direct investor interest and the country was the primary beneficiary from UK fund groups transferring assets to vehicles domiciled in Europe.
Fund managers like M&G Investments and Columbia Threadneedle have moved UK assets to Luxembourg funds since the Brexit referendum in a bid to ensure they remain open to European investors.
The Morningstar research is the latest evidence that Luxembourg's financial centre is benefiting from Brexit - which is now expected to take place at the end of October.
A similar report from funds transaction network Calastone found the Grand Duchy had pulled in around a third of all money flowing out of UK funds since the referendum itself, amounting to £20 billion.