The house that Christina Onassis was too scared to buy: Grade II-listed Mayfair mansion is sold for £45m decades after shipping heiress was put off by 'Satan-worshippers' living next door

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A Grade II listed property that was nearly bought by a shipping heiress - until fears over cultists next door put her off - has been sold with an asking price of £45million.

The mansion, in Balfour Place, Mayfair, boasts a staggering 19 bedrooms, seven reception rooms, six kitchens, 17 bathrooms and a roof terrace.

It was converted into six apartments a little over 20 years ago and the owner recently put it on the market for £45 million. 

Palatial: The mansion, in Balfour Place, Mayfair, boasts a staggering 19 bedrooms, seven reception rooms, six kitchens, 17 bathrooms and a roof terrace. The property incorporates the corner building, as well as a smaller side building, seen towards the bottom left of this picture

Opulent: A computer generated image of how the reception could look. The property was converted into six apartments a little over 20 years ago and the owner recently put it on the market for £45 million

Magnificent: An artist's rendition of how a walk-in closet could look at the palatial home. It originally featured large entertaining rooms and eight family bedrooms while the fourth and fifth floors were for staff

In August 1978 it nearly passed into the hands of the then 27-year-old heiress Christina Onassis, the only daughter of billionaire Greek shipping magnate Aristotle Onassis, who flew into London on her private jet for a one-day tour of houses in Mayfair and Belgravia

One of the homes she viewed was Number 7, however she backed out of buying it because a neighbouring property was being rented by the DeGrimston family - who gossips claimed were cult worshippers.

Their house was dubbed 'Satan's Cave' and it is thought this lead to the socialite getting cold feet on the purchase.

Scared off: Shipping heir Christina Onassis nearly bought the property, but was reportedly put off by 'devil-worshippers' next door

The Arts & Craft property, built in 1891, has been snapped up by a wealthy millionaire and could now be turned into one of London's newest super-homes.

Spread over 13,000sq/ft, the property is around 15 times the size of the average newbuild in the UK.

The property was marketed by Wetherell and Savills estate agents, with the deal confirmed by Peter Wetherell.

Due to a confidentiality agreement, Mr Wetherell would not confirm the final price paid or who had bought it.

However, if it is anywhere near the £45 million asking price, it will be among the biggest sales of 2014.

If the deal went through before the recent stamp duty change, the buyer would pay £3.15 million in tax on a £45 million pad.

However, if it was signed off after the deadline they will have to pay a staggering £5.3 million in stamp duty.

The most expensive publicly listed deal of 2014 was £50 million for a flat in Knightsbridge.

Mr Wetherell said: 'No.7 Balfour Place is one of the most magnificent Arts & Craft mansions in London.

'Built as a trophy property within the historic Grosvenor Estate it benefits from a prestigious Mayfair address, elegant architecture and rooms with princely proportions.

'As apartments it could be used as an investment to generate rental income, reinstated into a single residence, it could create one of London's finest mega-mansions, an outstanding home of world class quality and refined provenance.'

The property was designed by Eustace Balfour and has a five storey brick facade.

It originally featured large entertaining rooms and eight family bedrooms while the fourth and fifth floors were for staff.

Over the years it has had a number owners including several industrialists, a Dowager Countess and a City of London metal-trader magnate. 

Soaring: Property prices are on the rise in Mayfair with homes changing hands for £4,000 and £5,000 sq/ft

In August 1978 the then 27-year-old shipping heiress Christina Onassis viewed the property, but was reportedly put off because a neighbouring property was being rented by the DeGrimston family - who gossips claimed were cult worshippers

Over the years it has had a number owners including several industrialists, a Dowager Countess and a City of London metal-trader magnate

Due to a confidentiality agreement, the final price paid could not be confirmed, nor they buyer named

Number 7 was converted into six apartments in 1991 and the deal could prove to be a shrewd purchase.

Property prices are on the rise in Mayfair with homes changing hands for £4,000 and £5,000 sq/ft.

This could give 7 Balfour Place a potential value of between £52 and £65 million.

Some industry experts estimate values could hit £10,000 sq/ft in a decade - making it a £130 million home.