Complex sentence: The earl had been taking legal action in relation to a theft of some family antiques and artwork, and some acquaintances say he had complained of money problems, so they surmised that his disappearance may have something to do with this.
Split into simpler sentences: The earl had been taking legal action in relation to the theft of some family antiques and artwork. Some friends and acquaintances say he had complained of money problems, so they surmised that his disappearance may have had something to do with this.