On Wednesday the men, aged 43 and 51, who are both from Barnsley, were arrested on suspicion of the murder of Richard Dyson.
This follows the arrest and bail of two other men, aged 67 and 68, last week in relation to the case.
Richard was reported missing on November 25, 2019 by his daughter after he missed their arranged meeting.
He was last seen on November 17 at 11pm, walking along Sheffield Road, Hoyland.
Officers now believe he may have been killed after extensive enquiries to locate him.
A spokesperson for South Yorkshire Police said: “If you have information that may help our officers, please call 101 quoting incident number 459 of November 25, 2019.”