Treasury Holdings has launched legal action against NAMA to seek compensation over its decision to appoint receivers to the Battersea Power Station site.
Treasury, has also launched a challenge to the constitutionality of the legislation governing NAMA.
The moves are the latest in a legal battle waged by Treasury against NAMA, which last year with Lloyds Bank took control as creditors of the site.
The site is owned by Treasury's Real Estate Opportunities.
The decision could scupper a £5.5 billion sterling plan for homes and offices based around the derelict building which was approved by London's Wandsworth Council in November 2010.
A spokesman for Treasury Holdings said the company had initiated High Court proceedings in Dublin against NAMA for damages, and a separate challenge to the constitutionality of the NAMA legislation. He declined to give further details.
Treasury will claim it could have earned over £400m in management fees from the Battersea project over a 15-year span in addition to a share in the development's profits, a source close to the case told Reuters.
The 38-acre Battersea site has seen repeated redevelopment attempts fail in the past three decades since the red-brick power station closed and whose four towering chimneys are a feature on the London skyline.
Last month Treasury was granted approval by the High Court in Dublin to bring a legal challenge to the way parts of its business were put into receivership by NAMA.
Treasury has accused NAMA of rejecting offers to acquire loans without sufficient consideration and making a decision to call in the receivers without notifying the company for over a month. NAMA and Lloyds rejected a £262m bid for the Battersea site from a Malaysian firm in November. A month later, Ernst & Young was appointed administrator to four companies over £325m of debt linked to the site.