Philip Fenton says he intends to assist the British Horseracing Authority in "every way" after officials announced they are to visit the trainer's Co Tipperary yard in order to interview him and conduct tests on horses in his care holding Cheltenham Festival entries.
Fenton is facing charges of possessing alleged unlicensed substances, including anabolic steroids, following a visit to his yard by the Department of Agriculture in January 2012, with a court case adjourned until next month.
His horses on track for Cheltenham include former Champion Bumper winner Dunguib in the Coral Cup and Irish Hennessy hero Last Instalment, who is third-favourite for the Betfred Gold Cup.
Fenton told Press Association Sport: "I'm very pleased, and I shall assist them in every way.
"The sooner the better."
Last Instalment is owned by Gigginstown House Stud, whose boss Michael O'Leary reiterated on Sunday that he would be happy to subject his horses to BHA testing, should it be required.
And stud manager Eddie O'Leary responded to the latest news by saying: "We wrote to the BHA today to ask them to come and test Philip's horses, so it is what we wanted.
"We have absolutely nothing to hide and hopefully this will help clear a few things up.
"When Philip was raided it was January 2012 - Last Instalment won the Moriarty in February 2012 and was tested afterwards, that came back clean.
"The BHA is more than welcome to come over."
The BHA said that following consultation with the Irish Turf Club, it had been agreed that samples from Fenton's horses bound for Cheltenham will be collected by the BHA and fast-track testing will take place at HFL Sport Science, Newmarket, with the results of the tests available next week.
A statement from the BHA added that in addition to the sampling, Fenton will be interviewed and that the visit will form part of an ongoing process of gathering all relevant information regarding the issue. It is intended that both blood and hair samples are taken for testing, with substances able to be detected in hair samples for a greater period of time than is the case with either blood or urine.
It is understood negative samples would not automatically mean the horses would be allowed to run at Cheltenham, should other issues arise as part of the BHA trip.
BHA chief executive Paul Bittar said: "Following the adjournment of the court case, we want to take steps which serve to uphold public confidence in the relevant races at the Cheltenham Festival, and the sport in general. The testing of the Fenton-trained horses will form a part of the decision making process as to how best to achieve this objective.
"Any development or set of circumstances which brings the integrity of our sport into question is of considerable concern. The events of 2013 highlighted the need to increase the deterrent against the misuse of drugs and medication, and in particular anabolic steroids. Since then significant steps have been taken towards achieving a set of international minimum standards, with a number of jurisdictions adopting a zero-tolerance policy regarding the use of steroids in racing."