Gupta refuted evidence given by Andrew Hall that former Indian international Dinesh Mongia gave the instruction, saying Cairns told him between the innings and on the pitch as well.
It had earlier been claimed Cairns told Gupta to "get out now" when Gupta was on four runs.
Legspinner Karanveer said Mongia told him and his father everyone within the ICL knew about fixing. He told the court he then talked to Cairns during training about whether he had "spoken to Mongia", Cricinfo reported.
"This talk was about match-fixing, I was very much convinced," Karanveer told the court.
Off-spinner Sharma, speaking through a Hindi translator, said Cairns told him to "keep quiet" about match fixing, which led him to believe the Cantabrian was involved, Cricinfo reported.
Sharma, who has admitted to taking money for spot fixing, said he did not report Cairns to the ICL as it would have become a bigger problem for him.
Judge David Bean has allowed for a break in proceedings tomorrow, and will sum up on behalf of the claimant and defence the following day, before retiring to consider his verdict.
Cairns represented New Zealand in 62 tests, 215 one-day internationals and two Twenty20s. He made his test debut against Australia in 1989 and finished his international career with a Twenty20 match against West Indies in February 2006.