CLEARWATER — The Church of Scientology has offered the Clearwater Marine Aquarium nearly four times what the city is preparing to pay for a vacant downtown property.

The church offered the aquarium $15 million for the 1.4-acre lot, Scientology spokesman Ben Shaw confirmed, far exceeding the $4.25 million deal the City Council will vote to close on April 20.

It is the second time in three weeks Scientology leader David Miscavige has tried to outbid the city — aquarium officials passed on a $12.5 million offer the church made March 11, opting not to sell before the city has a chance to vote.

Aquarium CEO David Yates said Thursday that the nonprofit is committed to selling to the city, and no outside offer, no matter the amount, has changed that.

"The ball is in the city's hands," Yates said. "Nothing has changed. The offer we gave to the city still stands."

Shaw said the aquarium's rejection of an offer $10.75 million higher than what the city is poised to pay "calls into question the CMA board's adherence to its fiduciary duty as a charity."

"The church obviously cannot compete with this inappropriately intimate relationship between the city and CMA and will not be making any further offers," Shaw said.

The aquarium is in the midst of a fundraising campaign for a $50 million renovation of its aging facility on Island Estates that rescues, rehabilitates and exhibits marine life. It originally bought the downtown lot at the corner of Pierce Street and Osceola Avenue in 2012 for $2.1 million as part of a now-abandoned plan to relocate downtown.

The church wants the property, which is adjacent to its 13-story Oak Cove religious retreat, to build a swimming pool, a playground and other accommodations for its parishioners, Shaw said.

Consultants who designed the city's 10-year, $55 million waterfront redevelopment plan in February included the aquarium lot as property the city should ensure meets "the community's vision and productively contribute to downtown." It sits across the street from City Hall along a strip of Osceola Avenue that consultants said the city should redevelop to benefit the downtown and waterfront.

Miscavige held private meetings with City Council members March 14 to describe retail and entertainment he is planning to develop downtown. He insinuated the church's plans to bankroll a facade overhaul of Cleveland Street and recruit high-end retail to fill empty storefronts hinged on the church's ability to buy the aquarium property, City Council member Hoyt Hamilton said.

The church originally offered the aquarium $4.25 million for the lot in 2015, but aquarium officials held off to give the city time to complete its waterfront redevelopment plan and decide if it wanted to buy.

Appraisals the city commissioned in February estimated the market value of the land at $4.5 million and $4.66 million, respectively. That is up from the appraisals for the land the city received in 2015 at $4.36 million and $2.91 million.

The city leases its Harborview Center on Cleveland Street to the aquarium at no cost to display a memorabilia exhibit about Winter the dolphin. Yates added the relationship has mutual benefits, with the aquarium's $2 billion regional impact and 2.2 million hotel stays in Pinellas County over four years, according to a 2016 study by Tourism Economics.

Shaw pointed out the Church of Scientology, which has its international headquarters downtown, has an annual economic impact of $917 million, according to a 2014 Florida State University study.

As of Thursday, the majority of the City Council members said they intend to vote for buying the property, with only Bill Jonson and Robert Cundiff undecided.

City Council member Hoyt Hamilton said once city officials begin enhancing nearby Coachman Park, they can solicit bids from developers for ideas on how to redevelop the aquarium site to complement the waterfront.

"The land has great value for the development of Coachman Park," Hamilton said. "We want to see what the professionals bring to the table for that property. We can't do that if we don't own it."

Contact Tracey McManus at tmcmanus@tampabay.com or (727) 445-4151. Follow @TroMcManus.