The Sam Kavanagh cobalt inquiry could be delayed with Racing NSW stewards to consider applications for adjournments.

The panel has set aside four days - July 20, 21, 23 and 24 - to hear the case against six people charged in the Midsummer Sun affair.

The Kavanagh-trained Midsummer Sun returned positive results to caffeine and cobalt after his win in the Gosford Cup in January.

During the investigation, Kavanagh has given evidence he received the cobalt from Dr Tom Brennan of the Flemington Equine Clinic.

Brennan has also been charged along with practice manager Aaron Corby.

Disqualified harness racing trainer Mitchell Butterfield, harness racing identity John Camilleri and stablehand Michael O'Loughlin have all been charged over raceday treatment of Midsummer Sun.

"We have had applications from Dr Brennan and Mr Camilleri for further time which we will consider on Monday," chief steward Ray Murrihy said.

"Dr Brennan wishes to source more scientific evidence.

"We want to hear this as soon as possible."

Brennan has also been charged as part of a Victorian investigation into high cobalt levels returned by horses from the stables of Mark Kavanagh and Danny O'Brien.

Mark Kavanagh, the father of Sam, O'Brien, Peter Moody and the training partnership of Lee and Shannon Hope have all been charged with cobalt offences.