Estate agent may sue over £70m house

Lakshimi Mittal, one of the world's richest men, faces High Court action after the purchase of Britain's most expensive house.

The Indian steel tycoon, worth an estimated £3.5 billion, recently bought the 15-bedroom property next to Kensington Palace for a reported £70million.

But it has emerged estate agent Adina Kohn is reportedly considering suing the magnate for refusing to pay her finder's fee.

Ms Kohn, 52, believes she is entitled to £350,000 for making the initial contact between the Mittals and the property's former owner, Formula One boss Bernie Ecclestone.

She owns ASK Property Consultantsin Hampstead, finding homes for Premiership footballers and stars such as Kate Winslet and husband Sam Mendes - and charging a 0.5 per cent fee.

Jonathan Goldberg QC, acting on behalf of Ms Kohn, told the Independent on Sunday: "My client is confident she has a genuine case and is entitled to her money."

According to Ms Kohn she first showed the Mittals 18-19 Kensington Palace Gardens in 1997. The property is made up of the former Russian and Egyptian embassies.

The building now includes an underground car park, a swimming pool inlaid with precious stones, a Turkish bath and a ballroom.

The family offered £45million but were turned down and later told Ms Kohn not to proceed.

In April this year Ms Kohn discovered that the Mittals had completed the purchase only days after asking her to enquire about other properties in Kensington.

Ms Kohn was unavailable for comment last night. It is understood the Mittals - who were also unavailable for comment - claim to have bought the property using another agent. Mr Mittal, 53, courted controversy in 2002 when a "cash for favours" row erupted following a £125,000 donation to Labour.