RGL is also suing Link Fund Solutions (LFS), the fund's authorised corporate director, and said its claim could top 100 million pounds ($112 million).
Hargreaves declined to comment and LFS did not immediately respond to a request for comment over the weekend.
But it said last month it could fine LFS 50 million pounds and order a 306 million pound redress scheme over its management of the fund.
Law firms Leigh Day and Harcus Parker have each already filed claims against LFS on behalf of around 13,000 and 7,000 investors respectively.
They have expressed hope that they would be appointed joint claims managers at a December court hearing.