Jeffrey Epstein was seeking to triple the size of his estate on his private Caribbean island while his legal team was secretly trying to strike a sweetheart plea deal with federal prosecutors in a Florida sex-abuse case, according to a new report.

Permit records in the US Virgin Islands viewed by NBC News show that the multimillionaire financier was pursuing the huge renovation on the 70-acre island near St. Thomas, dubbed Little St. James, in the fall of 2007.

At the time, his lawyers were in negotiations with the feds in Miami who were investigating him for preying on young girls who were recruited to provide him with sexual massages, NBC News reported, citing court papers.

Under a non-prosecution agreement with then-Miami US Attorney Alex Acosta, Epstein served just 13 months of an 18-month sentence — and spent much of his time on work release.

Acosta recently resigned as President Trump’s secretary of labor amid controversy spurred by Epstein’s arrest in New Jersey on July 6 for allegedly sexually abusing dozens of minors at his Upper East Side mansion, as well his mansion in Palm Beach, Florida, between 2002 and 2005.

In November 2007, Epstein submitted a proposal created by Massachusetts-based design firm Maguire Group to transform his 8,124-square-foot island home into a mega-mansion — with a 16,747-square-foot addition, a new pool, a spa and an underground theater, according to the report.

“The alterations to the existing house will include a complete gutting of the kitchen, living room, office and guest rooms 1, 2 & 3, and installation of new roof structures and interiors,” according to the proposal cited by the network.

“The terrace north of the living room will be completely demolished and a new pool will be constructed in its place,” it said.

It was unclear if Epstein was given approval to move forward with all aspects of the upgrade plans.

The records viewed by NBC News at the Department of Planning and Natural Resources headquarters on St. Thomas did not specify whether he was granted a permit for all the work.

Department reps did not return a request for comment by the network.

Epstein, 66, who has pleaded not guilty, faces up to 45 years behind bars if convicted on charges of sex trafficking and conspiracy.