On the matter generally, see here. On the art connection, see Kelly Crow at the Wall Street Journal and Eileen Kinsella at artnet. And the Art Market Monitor says:
"The unanswered question surrounding Jho Low’s adventure in the art market is what he was hoping to accomplish with his art and real estate purposes. The assumption is that he was hoping to make quick gains by investing in art and real estate using borrowed money from 1MDB and multiplying that with leverage from other sources. But most of Low’s purchases were made at the top end of the market. In that range, Low was behaving more like a trophy or status buyer than a speculator."