Irish investment vehicle Sealink Funding is suing Citigroup ($50.35 -0.65%) over $513.3 million in residential-mortgage backed securities deals that allegedly contained toxic underlying mortgages. 

The structured-finance investment unit was known at the height of the mortgage bubble for its role in acquiring a slew of RMBS deals.

Sealink Funding has already gone after Citi's fellow big banks, JPMorgan Chase ($53.47 -0.16%), Royal Bank of Scotland ($10.24 -0.12%) and Bank of America ($13.38 0.065%) for RMBS deals that the investment vehicle believes contained material misrepresentations about the quality of the underlying mortgages.

In the latest suit filed in a New York state court, Sealink suggests Citi and related entities deposited, underwrote, sold and sponsored RMBS deals that contained misrepresented loan-to-value ratios and inaccurate information about the owner-occupancy status of various loans.

Sealink is suing for damages or rescissions on the RMBS transactions.

Citi declined to comment on the case.

kpanchuk@housingwire.com