Confirmatory tests on eight of nine Queensland samples have returned cobalt levels higher than the allowable threshold.

Results of further tests will not be known for at least two weeks.

"Those samples will now be sent to Sydney for referee analysis," Racing Queensland's integrity chief Wade Birch said.

He said the samples consisted of two from thoroughbred racing and and six from harness racing.

The six harness racing samples are from three trainers while there are two thoroughbred trainers involved.

"We received the results of those tests on Wednesday afternoon and as required under the Australian Rules of Racing, they will be sent for referee analysis to a laboratory in Sydney," Birch said.

Newcastle trainer Darren Smith has been charged with cobalt offences and will front Racing NSW stewards next week.

High profile Melbourne trainers Peter Moody, Mark Kavanagh and Danny O'Brien are the subject of an ongoing investigation into high levels returned by horses in their care.

The country Victorian training partnership of Lee and Shannon Hope has also had samples return levels above the threshold.

No charges have been laid in Victoria.