Building work costing £2.5 million is going ahead at the West Sussex mansion - dubbed the Roman Empire - of Chelsea Football Club's new billionaire chairman.

Russian oil tycoon Roman Abramovich's sports complex on his 300 acres at Rogate, near Midhurst will feature indoor and outdoor swimming pools, a fully-equipped gym and a bowling alley.

There will also be a play area for his five children, a steam room, sauna and jacuzzi.

Locals say when finished it will be bigger than their own sports centre.

Mr Abramovich, 36, paid £12 million for the Fyning Hill estate three years ago. It already has three polo grounds, formal gardens, a lake, a 50ft outdoor swimming pool, tennis court, go-kart track, clay pigeon shooting site, trout lake, rifle range and an equestrian centre.

There is a Twenties mansion, a second house, six cottages, a staff flat and four guest apartments.

It was once owned by King Hussein of Jordan, then media tycoon Kerry Packer.

Mr Abramovich, said to be worth £3.8 billion, was granted planning approval for the new sports complex last year.

Locals say he keeps a low profile but has been seen flying in by helicopter and driving through the village in a red Bentley.

Building work on the sports complex is expected to be completed later this year.