TOKYO, JAPAN — A Japanese company has defended its ownership of Van Gogh’s “Sunflowers”, obtained at auction in 1987 after the family of its former owner filed a US lawsuit demanding its return. The artwork — one of five original versions of the famous still life — was purchased by the predecessor of insurance firm Sompo Holdings at Christie’s in London for $40 million, making it briefly the world’s most expensive painting. It has been on display in Tokyo at Sompo’s art museum for 35 years, but recently became the subject of a legal battle centred on a previous sale...