Green’s Dictionary of Slang

to carry someone face-down, one person holding each limb; used on drunks or recalcitrant prisoners; later use of the term (see cit. 1974 onwards) means simply to be moved against one’s will, and no actual suspension is involved.

1884		Birmingham Wkly Post 15 Nov. 3/7: Deceased was ‘frog’s-marched’ – that is, with face downwards – from Deal to Walmer .
1901		W.A. Sun. Times (Perth) 27 Oct. 1/1: [of champagne] When the dear girls were ‘frog-marched’ off, even the dregs and heel-taps of the tawny tanglefoot had vanished.
1908		A.N. Lyons Arthur’s 166: They frog’s-marched ’im off to Vine Street.
1914		E. Pugh Cockney At Home 69: A bit of a dust in the Gray’s Inn-road, and Billy bein’ frog’s-marched off to the station.
1974		Galton & Simpson ‘Porn Yesterday’ Steptoe and Son [TV script] I was frog-marched up the Goldhawk Road in a policeman’s cape.
1989		H. Leonard Out After Dark 41: The shame of being frogmarched, unconscious, off the altar.
1997		L. Sante intro. in Riis How the Other Half Lives xv: Finally two cops frog-marched him to the nearest ferry.
2000		T. Udo Vatican Bloodbath 10: They were frogmarched before him.