Trainer Grant Allard has been suspended for four months and fined $5000 by Racing NSW stewards for failing to disclose the full benefit he received from the sale of a horse.

Allard, who trains on the NSW Central Coast, was penalised in relation to the sale of I Am Moses to Hong Kong in May 2018.

Stewards opened their inquiries into the matter in May this year, taking evidence from Allard, the horse's owners and a bloodstock agent, Daniel Flack, who brokered the transaction.

Stewards alleged Allard received $85,000 for the sale of I Am Moses after verbally agreeing with an owner to receive $80,000.

Flack, who earned a commission of $25,000 from the deal, originally told stewards he gave Allard $80,000 from the sale proceeds plus $5000 in outstanding training fees owed for another horse.

However, Allard's evidence to stewards was that the additional $5000 payment was made in error and at Friday's reconvened inquiry, Flack agreed the payment was erroneous.

When questioned regarding his conflicting version of events, Flack was unable to satisfy stewards with his explanation.

After taking into account several factors, including Allard's not guilty plea, his good record and the total of the undisclosed benefit, stewards suspended the trainer for four months, effective immediately.

He was also given a fine commensurate with the amount in dispute.