A studio used by young musicians is under threat from a basement development application and a new summer house linked to billionaire property mogul Sol Zakay.

The studio is owned by former TV presenter and charity patron Lady Anne Solti. The studio is used by the Solti Foundation, named after her late-husband Georg, and is used by young professional musicians as they start out.

The application comes from Brightwood Properties Ltd, listed in planning documents at the same Wigmore Street address where a host of Mr Zakay’s companies are registered. Another, S&A Residential Properties Ltd, is registered at the Avenue Road address where the basement development is planned, with Sol Zakay and Adi Zakay registered as directors.

According to the Land Registry, the house is owned by Brightwood Properties Limited, but with an address of 57/63 Line Wall Road in Gibraltar.

The application, which was due to be brought before Camden’s planning committee a week ago (Thu) but was put back to December 6, is to demolish most of the house, replace the summer house in its garden, and dig a basement for a swimming pool. The neo-classical facade will be kept.

Four years ago, Camden Council approved plans for a basement but nothing was built. The new proposal is smaller.

But in an objection to the application, Lady Solti said her studio is less than 20 metres from the planned dig, and could be negatively affected. She also alleges the house has never been fully occupied for the last 16 years.

Mr Zakay left Britain to move to Gibraltar in 2009, but returned to in 2013 to become executive chairman and CEO of property and investment group Topland, which he owns with his brother Eddie. According to Forbes, the pair are worth about £1.8billion.

Lady Solti said: “Many in this neighbourhood are deeply concerned about these plans.”

The Elsworthy Conservation Area Committee has also raised concerns about the proposals not being compliant with the Camden Plan, saying the basement could damage neighbouring gardens. Camden’s planning officers say this isn’t the case.

Lady Solti and Mr Zakay have been approached for comment, and the agent BB Partnership said it was unable to pass on details for Brightwood.