On Tuesday the club had denied reports that he had left, claiming that it was "just speculation".
However, the Warriors took to their official website later on in the evening to announce that the 51-year-old had called time on his Worcester career.
"Richard was brought into Worcester Warriors to get us promoted back to the Premiership, which he successfully achieved," said committee chairman Bill Bolsover.
"We then wanted to consolidate our position amongst the elite before breaking out of the bottom four. Despite all his hard work, effort, attention to detail and honesty, we have not continued the forward momentum.
"On behalf of everyone at Worcester Warriors, I would like to put on record our thanks and appreciation to Richard and we wish him well for the future."
Corin Palmer will take charge of the side for the remaining two games of the season.