TLKY,
Yes, at least l’chumra. Imagine if Berel decides to con someone by “selling” his house. So Berel finds a Shmerel and tells him he needs money quick, “if you give me cash you can have my house for 100 grand” and the house is worth 200 grand. Shmerel, not realizing that Berel is just planning on keeping the money and not leaving the house, gives Berel 100 grand in cash and they sign a shtar. When Shmerel shows up a week later with his U-haul, Berel says “I don’t know what you are talking about.”
When Shmerel takes his shtar to Bais Din, does he get the house or does he only get his money back?