Racing NSW boss Peter V'landys has launched defamation proceedings against the ABC and journalist Caro Meldrum-Hanna over an expose aired on 7.30 late last year, which revealed acts of cruelty against former racehorses across Australia.

Federal court documents obtained by the Herald state Mr V'landys will argue he was "greatly injured" by his portrayal in the segment, with his business, personal and professional reputation brought into "public disrepute, ridicule and contempt".

The two-year investigation, titled The Final Race, made allegations that hundreds of Australian racehorses were being sent to slaughterhouses. The segment aired on October 17 last year, just two days before the running of The Everest at Randwick, the highlight of Sydney's spring racing carnival.

Mr V'landys appeared in the program to respond to the claims on behalf of Racing NSW and stated in the segment that zero per cent of horses in NSW were being sent to the knackery.