In-form Tasmanian stayer Eastender has been scratched from the Group Two Adelaide Cup amid concerns of race day treatment.

The Barry Campbell-trained gelding, who has won his past four starts in his home state including the Devonport, Hobart and Launceston Cups, was among the leading contenders for Monday's feature race at Morphettville but was withdrawn on race morning.

"Eastender was ruled a late scratching by order of stewards at 10.55 Adelaide time this morning. That followed routine and regular inspections as we do at stables on race morning," Thoroughbred Racing SA's chief steward Johan Petzer told broadcaster racing.com.

"Stewards were concerned with some race day treatment practices in relation to Eastender."

Petzer said they deemed the integrity of racing would be better protected if the horse was withdrawn but said he could make no further comment with an inquiry to be conducted at a future date.