The Herald has learned agents representing the hotel's owner - Midlands-based businessman Kailash Suri - completed the sale of the historic building on Friday. Last month, Mr Suri announced the hotel was set to close, 18 months after he bought it promising a multi-million-pound makeover.
He claimed the Morice Square building was losing money "drastically".
But yesterday, Mr Suri, the Church of Scientology and property consultants King Sturge confirmed the building has been sold for a figure of about £1million.
Mr Suri reportedly bought the property for just under £1.5million in December 2008.
Marianne Rowell, spokesman for the Church of Scientology, said: "The contracts have been exchanged and we have completed the purchase of the building.
"It is still functioning as a hotel at the moment. Functions are continuing until June 22 when we take it on.
"We will then put in a planning application and fundraise to refurbish the building."
Scientologists have been searching for properties in Plymouth for the past three years with the view to opening a "bold" and "prominent" new church.
The current Church of Scientology in Ebrington Street is deemed as being "too small" for the needs of its followers. It has about 3,000 to 5,000 sq ft of floor space. The new church will have about 40,000 sq ft.
"Scientology, especially in the South West, is growing and that is why we need such a large premises," said Miss Rowell.
"There are about 12,000 scientologists in the region."
A planning application is likely to be submitted within the coming months to allow the refurbishment to take place to convert it into a church.
Miss Rowell said the church was keen to "enhance" the 110-year-old building, bringing it back to its original splendour.
Miss Rowell also hinted that a celebrity could officially open the building later this year. Another spokesman, Lili Mathieson, said the church was keen to change people's perceptions of the following.
As well as specific scientology events, the building - which will host about 150 volunteers and paid staff - will continue to welcome community events and functions.
"Most people freak out about us, but they don't actually know anything about us," said Miss Mathieson.
"We have had so many conversations about this issue.
"We would invite people to come in and look at what we do.
"We want to assist in the community and play a productive part of that community."
Miss Mathieson added that outreach workers from the church would also be looking to work within the Devonport community helping the local police.
As part of the plans, the Ebrington Street site will be renovated and converted into an information centre for the church.
Mr Suri, who also owns Plymouth's Reel Cinema, told The Herald: "The Church of Scientology has bought the building.
"Someone bought it on their behalf, completing the deal last Friday."
Mr Suri said he was sad to have sold the building but admitted the market was against him.
"It is a great shame, but the market was against us," he said.
Ifan Rhys-Jones, a business space agency surveyor at Plymouth's King Sturge, said: "It has been a long search and we have looked at a lot of properties.
"It has been quite hard to find a big enough building in Plymouth.
"My remit was to find something of around 50,000 sq ft which would be suitable for educational use and public assembly.
"We have worked hard to find them a suitable site."
Among the buildings which the scientologists looked at buying are Mills Bakery at the Royal William Yard in Stonehouse; the Royal Eye Infirmary in Mutley; the former University of Plymouth School of Architecture building opposite Bar Ha Ha in the city centre; and the former St Dunstan's Abbey School in Stonehouse.
An offer was made for the former St Dunstan's Abbey School site but it was not accepted.
Scientology was founded in 1954 by science fiction writer L Ron Hubbard.
It defines itself as ‘the study and handling of the spirit in relationship to itself, others and all of life’.
Scientology teaches that people are immortal spiritual beings who have forgotten their true nature.
In 2005, the Church of Scientology stated its worldwide membership to be eight million.
Members say there are 12,000 scientologists in the South West of England.
Scientology has been the subject of much criticism in the UK over the past few years.
Protesters have campaigned against the church’s presence in Plymouth on numerous occasions.
One of the many rumours surrounding Scientology is that it is linked to extraterrestrial civilisations with scientologists believing in alien interventions in Earthly events.