BING CROSBY's emotional support to those serving in World War 2 was only realised years after the conflict when his family stumbled upon a lost letter he had written, archive reports show.

 The iconic crooner is on screens this afternoon alongside the likes of Frank Sinatra and Grace Kelly, as they star in High Society. The 1956 musical comedy is airing on BBC Two from 2.20pm, and remains a firm favourite among Hollywood fans, thanks in part to Cole Porter's brilliant score. The story follows a playboy composer who is attempting to win back his ex-wife before she marries another man. 

His quest is complicated by a cynical reporter who has his own ambitions, in the process getting caught up in the romance.

The double Academy Award nominated film sees Sinatra, Kelly and Bing Crosby at the top of their game, and was in the top 10 best performing films in the year of its release.

While much is known about Crosby's incredible musical career — which saw him lay claim to the biggest ever selling single, ‘White Christmas’ — occasional surprises about his life still crop up.

This included the time when his family were left stunned after unearthing his belongings, which included a letter detailing how he helped entertain troops during World War 2.