The head of a federal aged care inspection agency says he wants answers as to how his organisation allowed the Oakden mental health facility in Adelaide to continue operating following an audit. The Australian Aged Care Quality Agency accredited the Makk and McLeay aged care home in February last year. This month, the South Australian Government announced the facility would be shut down after an investigation uncovered mistreatment of patients dating back a number of years. The agency’s chief executive, Nick Ryan, visited the home on Thursday and said it was one of the “poorest examples” of nursing homes he had experienced. “I’m deeply concerned by what I observed [on Thursday],” he said.