Racing Victoria will review its third party contract with a company responsible for providing photo finish equipment after a delay of more than an hour at Werribee races.

The person expected on course on Friday from Amalgamated Photo Finish failed to arrive because of a rostering error, causing the delay while alternative arrangements were made.

Because of the late start, jockey Chris Symons had to be released from rides in two races to allow him time to get to Moonee Valley for the night meeting while fellow rider Noel Callow was replaced in the first race at Moonee Valley.

"Today's delay is unacceptable and we will now be reviewing our arrangements with the third party service provider to ensure that it doesn't occur again," RV spokesman Shaun Kelly said.

The importance of the photo finish was underlined by a dead-heat in the second race at Werribee.