IT IS the riddle of the sand wedge. A huge sign on an approach road to the M50 close to Dublin airport is warning that golf is just a “passport for a dirty weekend away with the lads” and, while it has gone viral over the past two days, the identity of the “naive wife” behind it was last night still shrouded in mystery.

The advertisement, which said so much yet revealed so little, was draped over the side of an articulated lorry trailer left in a field beside the N2 slip road which leads on to the M50. In full, it reads: “Golf is a passport for a dirty weekend away with the lads. Wake up girls . . . A naive wife.”

Social-media networks were yesterday awash with speculation as to who might be behind the sign, with some people expressing sympathy for the scorned wife. Others insisted it was a marketing stunt for an unidentified business.

The trailer was originally owned by Howarth Bros haulage company and its name is still emblazoned on the truck. When Howarth Bros was contacted yesterday, a spokeswoman said “every man and his dog from Ireland” had been calling to see if she could lead them to the “naive wife” but she had “no idea what the story is behind the ad” as the company had sold the trailer to a haulage firm six years ago.