The man in question is Denis O’Brien, the Irish entrepreneur named by FourFourTwo, the football magazine, as the wealthiest man involved in Scottish football.

O’Brien owns a 2.82% stake in Celtic, small enough to keep him out of the public eye, but is reportedly worth around £1.73bn, making him even richer than Dermot Desmond. Not that Celtic’s majority shareholder is soon be out on the streets busking given he is said to be still worth approximately £1bn.

O’Brien has been involved with Celtic since 2006 when he bought Martin O’Neill’s shares and is said to have invested around £1m in the Parkhead club. But who is he?

A former business partner of Desmond’s, the Dubliner made his fortune primarily from the telecoms industry. He was the youngest Irish citizen to become a billionaire two years ago, although the value of his empire has decreased in the past year by more than £200m mainly due to the drop in value of his shareholding in The Independent newspaper group.

Not that that should cause him too many sleepless nights. O’Brien, who resides in Malta as a tax exile after a period living in Portugal, continues to prosper in other areas, in particular his two Bermuda-based Digicel Group mobile phone companies that operate in 31 countries and are said to be worth around £1.2bn alone.

A refinancing of those firms two years ago earned the 51 year-old £375m in cash, which certainly beats working for a living.

After dabbling in an unsuccessful home shopping channel, and then radio stations, O’Brien got his big break in 1991 when he established Esat Telecom, eventually selling it to BT for just short of £2.5bn.

O’Brien is said to be a big sports fan and generous with his money. He agreed last year to pay half the wages of Giovanni Trapattoni and his backroom staff when they were hired by the Republic of Ireland national team, and also owns the Quinta do Lago golf complex in Portugal.

Two years ago, he gave the Irish cricket team £100,000 for reaching the Super Eight stage of the World Cup and also owns a £17m Gulfstream Jet and a house in Dublin said to be worth around £23m. Yes, but is he happy?