In 2002, Jasper Conran went househunting for a weekend hideaway. To the surprise not only of those who know him — but also apparently of the designer himself — he eventually plumped for a £1.35m moated manor house in a fairly unfashionable part of rural Suffolk.

In the four years since, Conran, 46, has lavished tens of thousands of pounds on Flemings Hall, set in six acres of gloriously blowsy gardens, in Bedingfield, 15 miles north of Ipswich. Now, it seems, he is selling up.

Unusually for him, the sale of the £2m property is secretive. Although the house has been advertised in Country Life, the Ipswich office of Savills, the agency handling the sale, declined to confirm the identity of the seller, who “wishes to remain anonymous for now”.

Nor is it clear where Conran will go — although he will not be homeless, thanks to a London flat overlooking Hyde Park, which he has described as “three ballrooms and a bedroom”, and a condo in Miami.

It is all a long way from the tiny one-bed flat in Earls Court to which the designer was obliged to retreat during the recession of the early 1990s. Business began to pick up later that decade, and Conran now works out of a £6m-restored Grade II-listed townhouse in Mayfair. His own company has an annual turnover of £250m and he has added to his wealth with his profitable J line for Debenhams, and other design commissions, including china for Wedgwood and a range for Waterford Crystal. Last year, he reputedly earned more than his father, Sir Terence, who founded Habitat, making him the most successful British designer after Sir Paul Smith.

There was no more potent symbol of the recovery of Conran Jr’s fortunes than his purchase of Flemings Hall, described by Norman Scarfe, in his 1960 Shell Guide to the county, “as one of the most romantically beautiful houses in Suffolk”.

Built on the site of an old Saxon stronghold, the house itself, now Grade II*-listed, dates from the 13th century and had its first makeover in the 1500s, when a first floor was put in. It has since been extended and now features a heated swimming pool.

When Conran moved in, he ripped up the blue nylon carpets, exposing beautiful oak floorboards and herringbone tiles. He hacked Artex from the walls of the living room and spent a fortune renewing the lime plaster throughout. All the fireplaces were unblocked.

One less successful design touch was to colour-co-ordinate the light switches with the walls to make sure the electrical fittings did not stand out. The result: he couldn’t find a single switch in the dark.

Conran has devoted most of his energies to the garden, however, which is the height of relaxed, yet formal planting. With the help of Billy Freeman, the full-time gardener who came with the house — and will continue to do so — and Branch Out, a local group of adults with learning difficulties who have helped every week for more than three years, Conran has removed 16 tons of concrete patio, replaced gravel with grass and planted 85 trees, including varieties of fruit, cricket-bat willows, beech and oak.

The lavender-edged, one-acre kitchen garden now has enough food to feed all the guests salad lettuces, asparagus, carrots, potatoes, peas and broad beans. He has planted enough flowers to fill a dozen or so rooms with freshly cut stems.

“It’s not about showing off, it’s about recreating the perfect summer day of your imagination,” he has said. For him, “the function of a house with nine bedrooms is one where people can be comfortable, read newspapers with their feet on the sofas”.

It is also a house that is perfect for parties, and Conran has held a few. Last Christmas he put up a vast tent big enough to accommodate a table covered with a 30ft tablecloth that had belonged to Queen Victoria. At another party, to celebrate his brother Sebastian’s birthday, he had the chef from the Blueprint Cafe in Butlers Wharf, in east London, brought in, along with 18 tons of kitchen equipment.

Home to the Bedingfield family for 900 years of its life, Flemings Hall was bought in the 1960s by Angus McBean, the theatrical photographer, who lived there with his assistant David Ball and their friend Norman Kelvin.

The property is believed to be haunted. Conran apparently tried to dispel the ghosts by playing the World Service at 3am, before shouting at the unseen guests: “If you keep waking me up, you’re going to see a queue of priests of every denomination filing all the way down the road outside.”

It may not be just the ghosts that need to worry, however. “I find it quite comforting to think that I’ve spent all this time and money, and if anyone comes along after I’m gone and messes it up, my God, I’ll be smashing the crockery and spinning through this house causing devastation,” he said recently. Future owners take note.

Flemings Hall is for sale for £2m with Savills, 01473 234 800, www.savills.co.uk

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