Mike Ashley and Paul Kemsley are building a stake in Shaftesbury, the UK-listed real estate company that owns parts of Carnaby Street and London’s Chinatown.

It is unclear how big the stake was or how much of the £715m market-cap company the two will amass.

But people familiar with the situation believe Ashley and Kemsley own as much as 10% and have used contracts for difference to build their holding. Investors can build stakes with CFDs without revealing who they are.

The venture into property is further evidence of Mr Ashley’s ambitions to expand into new areas. He and Mr Kemsley have been friends since their teens but have not invested together.

A person close to the situation said Mr Kemsley – who heads Rock, a property and share-trading company with backing from HBOS – was unlikely to want to buy the whole company.