The conduct of companies employed to provide security at the 2020 FIFA World Cup stadiums was sabotaging safety at the tournament, the Congress of South African Trade Unions (Cosatu) said on Thursday.

"Cosatu condemns conduct of security bosses that sabotages safety of FIFA World Cup," Cosatu's Western Cape secretary Tony Ehrenreich said in a statement.

Ehrenreich was commenting on the strike by Stallion Security employees, which resulted in thousands of police officers replacing the guards. Police officers being pulled from normal duties left communities exposed, he said.

The security companies had known of brewing problems for weeks and did nothing, he claimed.

"This conduct by the security companies is now being sanctioned by South African government, who is bailing them out with the South African Police Services."

He said that Cosatu's offer to help resolve the problem had been rejected by the companies.

Ehrenreich said that Stallion Security guards were working at Ellis Park stadium in Johannesburg when 43 people died during a stampede on April 11, 2001.

The investigation found that one of the 14 factors that led to the disaster was corruption on the part of certain members of the security personnel. A total of 62 000 tickets for the Orlando Pirates and Kaizer Chiefs derby were printed, but an inquiry into the disaster found that about 80 000 people attended the match.

Stallion Security said it would issue a statement later on Thursday.