Now his exasperated wife, the Secretary of State for Culture, Tessa Jowell, has been privately saying that she wishes she could slap an Asbo on him, to restrain him from doing anything else that might get his name in the newspapers - here or in Italy.
The couple are just back from visiting their son in Florida, where their family break was disturbed by the wholly unexpected appearance of a Daily Mail journalist who hoped to extract more information about his Italian links.
He had been speaking freely to journalists, until his Italian lawyer told him to stop. He described himself to the Sunday Telegraph as "a complete idiot". Talking to The Independent he described one of his actions as "completely insane". But he has been consistent on two points - he is sure he has done nothing wrong; and none of the stories swirling around his name in any way involved his wife.
It is a story that began a quarter of a century ago, when a youngish barrister who was thinking that he might like a change of direction in his professional life met an English-speaking Italian named Marino Bastianini, who worked for one of Milan's leading law firms, Carnelutti Studio Legale Associato. Mr Bastianini persuaded him to become involved in supplying legal advice to Italian firms wanting to expand into Britain. Their association became so close and profitable that the youngest of Mr Mills's five children is named Matthew Marino in Mr Bastianini's honour.
The connection also inspired Mr Mills to learn Italian, which he did impressively quickly. He has a gift for languages, traceable to his boyhood, when his father, Kenneth, was a big league spy. At the end of the war, Kenneth Mills was running MI5's operations from Gibraltar. Later, he was transferred to Jamaica and - according to a family legend - personally foiled an attempted revolution in Cuba. Its leader, Fidel Castro, survived to try again.
Kenneth Mills had a house in Spain, and his son David, born in 1944, was speaking Spanish almost as soon as he learnt English. He added French and the classics, Greek and Latin, to his repertoire before going up to University College, Oxford, in the early 1960s, to read politics and economics.
David Mills's connection with Carnelutti brought him a huge number of Italian clients, including one famous connection that perhaps he now has cause to regret. Documents at Companies House show that in March 1980 he set up Reteitalia, whose principal activity was the purchase and sale of film rights. It was owned by an Italian holding company, Fininvest. The head of Fininvest - who was also briefly a director of Reteitalia - was Silvio Berlusconi. Berlusconi and his daughter visited London in 1995, and reportedly had a long meeting with David Mills in the plush surroundings of the Garrick Club.
One aspect of company law that interested Berlusconi and others was the use of offshore companies registered in tax havens like the Virgin Islands. To this end, Mr Mills set up a firm called CMM Corporate Services - standing for Carnelutti Mackenzie Mills - which he sold in June 1994 for £750,000, including, reputedly, £675,000 for his personal stake. He then set up his own firm, Mackenzie Mills, which merged in October 1995 with a high-class London firm called Withers, in which Mr Mills became senior partner. Withers' private and corporate clients included the Duke of Marlborough and Benetton.
He had an early warning 10 years ago of the sort of trouble his Italian links might land him in when the Public Prosecutor in Milan applied to the Home Secretary, Michael Howard, for British help in investigating bribery and corruption allegations involving Mr Berlusconi. The investigative trail had led the Italians to CMM Corporate Services, now operating out of Switzerland, under Italian management. No sooner had they applied to the Swiss authorities for help than the people who ran CMM moved out, shifting operations to an office in Regent Street. The Milanese prosecutors then asked Mr Howard, to arrange for the Regent Street offices to be raided. And they wanted the fraud squad to pay a call on Mr Mills at Withers.
When the Serious Fraud Office applied for a search warrant, they made it clear the only people being investigated were those who had been running CMM Corporate Services since Mr Mills sold it. The officer in charge told the magistrates that "in the case of Mr Mills, who is a professional man and a member of a highly respected professional firm, I believe that he would comply with a notice to produce such documents as he has in his possession". All that followed to disturb a working day at Withers was a gentlemanly visit by SFO officers and their Italian interpreters.
It is not surprising that SFO officials should be so clear about who David Mills was. He was the brother-in-law of their former director, Barbara Mills, who was by then Director of Public Prosecutions.
Dame Barbara is married to John Mills, a leading Camden councillor and a business tycoon who has probably made even more money than his brother. David Mills and Tessa Jowell are also former Camden councillors, which is how they met. Both had to go through difficult marriage break-ups, made worse by the resulting publicity when she stood for Labour in a parliamentary by-election, before they married in 1979 (below). David Mills had three children by his first marriage, and has had two by his second, and now has three grandchildren.
A more cautious man might have taken these early brushes with bad publicity as a warning of the trouble ahead, particularly after his wife became a senior government minister in 1997. Her elevation naturally extended Mr Mills's already impressive social contacts. When a Freedom of Information Act request disgorged the list of people who have dined at Chequers at taxpayers' expense, no one was surprised to find David Mills and Tessa Jowell on the list. He has also played golf frequently with Alastair Campbell. He has cooked for Ruth Rogers, of the River Café, and for Albert Roux, proprietor of Le Gavroche. He has dined with Elisabeth Murdoch and Matthew Freud. Peter Mandelson and David Blunkett have joined the stream of guests at his second home, in Gloucestershire. He is so Blairite that he even has the same heart condition as Tony Blair. He has loved to mix with the famous, in Britain and in Italy, but seemed to be blind to the accompanying risk.
"My father is a highly, highly intelligent man," one of his children said. "There has never been a question that I have asked my Dad that he didn't know how to answer. I grew up to the theme of Mozart clarinet solos that he used to play. He's a real polymath.
"With that kind of brilliance there comes a certain sense that success follows. He has lived in very rarefied circles for a very long time. He's great fun. He's very, very generous. There's nowhere that he doesn't have access to. With that comes a slightly unrealistic take on what you can get away with.
"Dad's finances have always been an absolutely closed book to any of the family. Most of the stuff we're reading now is news to all of us, including Tessa. He has not kept any of us in the loop."
The Labour Government was not many months old before Mr Mills received a warning about the publicity a minister's husband can attract. One of Labour's election promises was to end tobacco sponsorship of sport, but in November 1997, it emerged that the British Government was actually trying to protect Formula 1 racing from an EU-wide ban. Mr Mills was both legal adviser to and a former director of Benetton Formula 1. His wife, as Minister for Public Health, was responsible for government policy on smoking.
The resulting uproar put the couple's loyalty through a stern test. It was not then publicly known that it was not her idea to ask for an exemption for Formula 1. She had privately argued against it. After a few days in which the couple shut up and took the flak, they were saved by the much bigger furore that erupted when it emerged that the Formula 1 boss Bernie Ecclestone had secretly donated £1m to Labour funds.
Then, as Italian prosecutors searched for the money trails leading to and from Silvio Berlusconi, Mr Mills was given another insight into how unpleasant life can be, even for a polymath who has known nothing but success all his life. He now has 14 filing cabinets full of documents forwarded by the Italian authorities, in which he has read statements made by people he has known for years, as business associates and - he imagined - as friends who, according to one of his children, "have sold him down the Swannee to save their own skins".
He gave evidence at Berlusconi's two trials, in 1997 and 1998, in which - to quote his own words in a now notorious letter to his accountants - he "told no lies but turned some tricky corners". The Italian prosecutors have dropped an allegation that he lied in court, but he certainly took a professional risk. Last week, he read Berlusconi was saying that they had never met but that Mills had "used my name to cover himself from the tax authorities in his own country".
Mr Berlusconi has claimed that the investigation into his finances is a left-wing plot. Mr Mills has been more self-flagellating. Overconfidence may have led him into some foolish actions, he admits, but he is adamant that he has done nothing against the law. On that point, he may have a tough time convincing a court in Italy.
A Life in Brief
FAMILY Married to Tessa Jowell, two children, three from earlier marriage
CAREER Founder of Mackenzie Mills, merged with Withers in 1995. In 2001 joined law firm Gordon Dadds as an equity partner. Set up Mills Saint James in 2003.
HE SAYS "The way in which I had been able to give my evidence (I told no lies, but I turned some very tricky corners, to put it mildly) had kept Mr B out of a great deal of trouble that I would have landed him in if I had said all I knew."
THEY SAY "Somebody used my name to cover himself from the tax authorities in his own country and so as not to have to tell the partners of his legal practice exactly what he had pocketed." - Silvio Berlusconi, Italy's Prime Minister.Reuse content