Dozens of artists connected to the Whitney Museum of American Art — including more than half of those selected for the coming Biennial — have called for the resignation of a museum board member whose company sells tear gas that activists and the art publication Hyperallergic say was used on migrants at the Mexican border.

It was the latest volley in a monthslong series of letters involving the board member, Warren B. Kanders, museum employees, artists and academics over his role as owner, chairman and chief executive of the Safariland Group, which sells multiple lines of military and law enforcement equipment including tear gas. According to Hyperallergic, photos showed tear gas canisters marked with the company’s name at a site where the American authorities used tear gas to disperse hundreds of migrants running toward a crossing that leads from Tijuana to San Diego last fall.

On Monday, artists, including Dread Scott, Barbara Kruger, Cameron Rowland, Nan Goldin, Yvonne Rainer, Hans Haacke, Andrea Fraser and Laura Poitras, whose work is owned or has been exhibited by the Whitney, added their names to a letter published this month by scholars and critics who urged the museum to remove Mr. Kanders from his position as a vice chairman of the board.

Forty-six of the 75 artists and collectives chosen for the Biennial, which opens May 17, also signed the letter, which said tear gas from Mr. Kander’s company had been used against Palestinians in the Middle East and protesters in Egypt, Puerto Rico and Standing Rock, N.D., and called for a conversation about private funding of cultural institutions.