HUNDREDS of frozen urine samples may soon reveal if Victorian racing has a dark past of illegal drug use.

MATT STEWART reports for the HERALD SUN that Racing Victoria chief steward Terry Bailey said he was confident there would be no more positive drug tests to cobalt from late last year; from the time the first illegal levels from three stables were recorded at the end of the spring carnival and before the Australian Racing Board issued a warning over supplement use in mid-January.

But Bailey also revealed Racing Victoria was sitting on a cache of frozen samples taken some years ago, which could be thawed out and retested by new technology in coming months.

Asked if the testing of those samples for EPO, cobalt, peptides and a raft of other illegal drugs was a priority, Bailey said: “It’s at the forefront of our minds.’’

Bailey said samples frozen for some years had been thawed out and analysed “sometime in the last 12 months’’ and said none returned positive tests.

But he said technology in testing for many substances, particularly peptides, was becoming more sophisticated and that “when we can properly test for a, b and c then we will revisit the frozen samples.’’

Bailey said form spikes, betting plunges — or major drifts — and other factors, such as mandatory testing of black-type winners, determined which horses were subjected to urine tests, which were then put on ice.

Bailey said Racing Victoria’s veterinary team met regularly to discuss advancements in technology, adding he would be advised by chief vet Brian Stewart when it would be reasonable to retest samples from an era believed to be from about 2008 until 2012.

Racing NSW stewards this week revealed a frozen sample taken from Black Caviar had not returned illegal levels of cobalt.

Black Caviar’s trainer Peter Moody had implored stewards to examine the legendary mare’s frozen samples in a bid to preserve her reputation.

The sample was taken the day she reeled in Hay List to win the 2011 T.J. SmithStakes, regarded among her most courageous wins.

On hearing Black Caviar’s drug test was negative, Moody said: “I know she raced on her own ability and this shows it from one of the toughest tests she faced in her career.’’

He applauded Racing NSW’s proactivness in quashing innuendo by testing the sample.

Four Victorian stables face investigations after their horses returned illegal cobalt levels and three — Danny O’Brien, Mark Kavanagh and Moody — were advised on January 14 of positive tests returned in the October/November period.

O’Brien was told on Tuesday that another of his horses, sprinter Bullpit, has tested positive to cobalt after it won at Moonee Valley during the same period.

While Bailey doubted there would be any more illegal readings, O’Brien has said every one of his 80-plus horses was given the same supplement regimen he claims has pushed some readings above the 200 microgram threshold.

It is believed O’Brien’s positive tests — and Moody’s and Kavanagh’s — sit just above the threshold.