KEY BISCAYNE, Fla. -

The Sony Open tennis tournament on Key Biscayne wrapped up its final match Sunday and a point of contention between two parties about the possible development of the Crandon Park Tennis Center is still underway.

In 1940, Bruce Matheson's family donated roughly 900 acres of Key Biscayne land to Miami-Dade County. Its sole purpose was to become and stay a public park for all time.

"Crandon Park was given to all citizens of Dade County and their guests for public park purposes only," said Matheson.

According to a 1993 settlement agreement and master plan made with the county, no new permanent structures are allowed on the tennis center. But a November 2012 referendum aimed at "developing the tennis center facilities" was approved with 72 percent of voter support against Matheson's wishes. He then filed a lawsuit to stop the vote.

"The master plan should represent the will of the people," said Adam Barrett, tournament director of the Sony Open, which is operated by IMG.

The tournament is planning a $30 million to $50 million improvement project that would include a new clubhouse and possibly two permanent smaller stadium courts.

Crandon pic 2

"What we want is to build a better park for the public on a year-round basis and a better park to house a world class event," said Barrett.

Barrett said the project would add about an acre of green space, where now there is just asphalt and dead grass. He also said having permanent facilities would give the opportunity for better landscaping and more indigenous plant growth.

"The expansions are completely contrary to the settlement agreement, the master plan and the court order requiring Miami-Dade County not put any new structures on the Crandon Park Tennis Center site," Matheson said.

Miami-Dade County and the Matheson family will go to court to follow up on the lawsuit April 3.