A German landlord who has long been at the centre of controversy in his country of origin has become one of London's biggest property tycoons.

70-year old Henning Conle, long-renowned in his home country of Germany for shoddy buildings and acrimonious tenant disputes, has amassed a portfolio of prime property in London worth nearly 2 billion pounds.

His London acquisitions encompass a bevy of iconic or historically significant buildings at the centre of the city, including the Kensington Roof Gardens complex, the Plaza shopping centre on Oxford Street, Stratton House, which is home to Manchester United’s London offices, as well as the art deco Shell Mex House on the Strand, which Conle acquired just last year for an impressive 610 million pounds.

While Conle has refrained from courting attention, acquiring his British real estate holdings via a Luxembourg-registered company called Sirosa, his recent spate of purchasing activity and the prominence of some of his acquisitions have drawn keen attention from London’s property, as well as turned the spotlight on controversial past.

Conle’s portfolio of high-prestige period buildings in London stands in stark contrast to his real estate operations back home, where he is renowned for shoddy building work and skimping on repairs.

He first became the target of accusations from tenants in the Ruhr region over shabby buildings and roughhouse treatment back in the 1980s.

In the 1990s, Hamburg newspapers took to calling Conle “the Phantom” because of his disinterest in the maintenance and upkeep of his portfolio of flats in the city, which may have numbered up to 2,500 units. Conle had a reputation for being slow to assist tenants in the case of severe structural mishaps such as ruptured water pipes.

In 1998, a Hamburg court further ruled that the bullying tactics Conle employed to deal with late-paying tenants were illegal.

While Conle may not have been the most concerned or solicitous of landlords back in Germany, his acumen as a property investor is beyond dispute.

The value of prime real estate in the centre of London rose continuously throughout the Global Financial Crisis, with one real estate agent who previously worked with Conle describing his purchases of commercial property as a “one-way bet.”

Commercial property possesses the added advantage of dispensing with the burden of addressing the wants and needs of residents – the one issue which has bedevilled Conle’s career in the past, thus allowing owners to be more passive.